Author: Maciamo Hay. (Written on 6th February 2019. Last updated in March 2020.)
Origins, People & Government
The ancient Romans were originally an Italic tribe from the Latium, known as the Latins. Their language was also known as Latin. The Italics were an Indo-European people closely related to the Celts of Central Europe, from whom they probably split around 1200 BCE when one group crossed the Alps to settle in Italy.
Legend has it that the city of Rome was founded by Romulus in 753 BCE, but archeological evidence showed that the site had been occupied since at least 1000 BCE.
From early in Roman history, the citizens of Rome were divided between the patricians, the ruling class supposedly descended of the first 100 senators appointed by Romulus, and the plebeians (or plebs) making up the rest of the free citizenry.
Originally the citizens of Rome were called Quirites, a name thought to come from *co-uiri-um, "assembly of the men", which shares a root with the curiae (popular assemblies to which Roman citizens had to belong), perhaps also with Quirinus (Sabine god of war, and early god of the Roman state) and Quirinal Hill (one of the seven hills of Rome, first settled by the Sabines).
Rome was originally a kingdom, but in 509 BCE, the Romans rose up against the tyranny of the king and established a republic led by two consuls elected for one year, so as to prevent abuses of power. The reason why Julius Caesar was assassinated in 44 BCE was that some senators felt that he had accumulated too much power and may attempt to re-establish a monarchy with himself as king. Augustus is considered the first emperor, but he was careful never to use that title, preferring to call himself Princeps Civitatis ("First Citizen of the State") to give the illusion of the continuity of the Republic (see Principate).
During the Roman Republic (509 to 27 BCE), senators were elected to political offices following the so-called cursus honorum, which determined the minimum age and sequential order for each of public office. Each office was held for one year. The highest office was that of consul (two of them), who acted as the political and military heads of the state. Right under them were the praetors, who administered justice and could exercise the functions of the consuls in their absence. Then came the aediles, who were responsible for the urban maintenance of Rome, including roads, water supply and food, the regulation of public festivals, and the enforcement of public order. The most junior magisterial office was that of quaestor, who performed financial and legal duties. Other special offices included that of censor (mostly held by ex-consuls), who supervised public morality, and tribune of the plebs (held by wealthy plebeians), who intervened on behalf of plebeians in legal matters and could veto the actions of the consuls and other magistrates to protect their interests as a class.
The Roman Senate was the backbone of the Republic. It controlled public finances, civil administration and foreign policy. Senators were not democratically elected by appointed by consuls, and later by censors. The Republic also had three voting assemblies: the Plebeian Council, the Centuriate Assembly and the Tribal Assembly, who among others elected magistrates, but were generally subservient to the Senate in terms of sovereign power. The Republic was governed by the Senate and People of Rome, very much in that order. It was more flexible and democratic than Sparta, but less vulnerable to popular whims than classical Athens. 
The popular assemblies were presided over by a consul or other magistrate to make declarations of war and peace, to pass laws and for elections. Unlike in Athens and other democracies, these assemblies simply voted yes or no on proposals put to them and were not permitted to debate issues or to propose votes of their own. Such discussion took place in the Senate. 
The term 'empire' (imperium in Latin) had a very different meaning to the Romans as it does today. Imperium was the right to command armies and preside over the Senate. During the Republic this was the preserve of the two consuls and of the praetors. Later, the Princeps Civitatis (emperor) also held imperium.
Justice in the early days of the Republic was based on customary unwritten law, exclusively interpreted by upper-class priests, the pontifices. In 450 BCE opposition to this arbitrary patrician justice led to the composition of the Twelve Tables, the first recorded Roman laws, which stated the rights and duties of the Roman citizen. This strengthened the position of the plebeians, and in 367 BCE a law was passed allowing plebeians to stand for election as consul. Eventually, plebeians gained access to almost all major political and religious offices. By the end of the 4th century, the enslavement of Roman citizens for debt had been banned and all citizens possessed the right of provocatio ad populum, the right of appeal to the whole people against decisions made by a magistrate. The long struggle between patricians and plebeians culminated in 287 BCE with the Lex Hortensia, which made all resolutions passed by the Plebeian Council, known as plebiscites, binding on all the population, including patricians. 
From 340 BCE, Rome started expanding its territory by waging war with its neighbours, first the other Latin tribes, then the Samnites and Umbrians (other Italic peoples), the Etruscans and the Greeks of southern Italy, who were all conquered by 270 BCE. All these people became assimilated by the Romans and acquired Roman citizenship in 88 BCE at the end of the Social War. During the Late Republican period, the Roman ethnicity was no longer purely Italic, but increasingly a meger of Italic, Greek and Etruscan people.
One of the great political innovations of the Romans was to absorb the peoples it defeated instead of just enslaving or plundering them as was normal practice at the time. Neighbouring Latin towns became the first allies of Rome. As such they did not have to pay tribute but were required to provide a fixed number of soldiers who served in the Roman army under Roman generals. The Latins were entitled to a fair share of any plunder gained in war and were promised the protection of Rome against outside aggressors. Romans and Latins could contract valid economic agreements that were legally binding on both parties, and they could intermarry without the children being regarded as illegitimate. The same principle was later extended to other conquered tribes of the Italian peninsula. 
The Roman social structure was pyramidal, with the senatorial aristocracy at the top, followed by the equites (equestrians or knights), then the farmers and craftsmen, and finally the numerous slaves who provided much of the workforce. But this structure was never rigid, and the ability of outstanding men outside the hereditary elite to advance themselves was one of Rome’s great strengths. In the late Republic, the equestrian class became heavily involved in trade and industry, which were of only limited importance in early Rome. 
In 149 BCE, a permanent criminal court was established at Rome with the chief purpose of giving foreigners compensation and the right of redress against extortion by their Roman rulers. No ancient Mediterranean empire had ever systematically tried to do this before. This demonstrates a genuine political will to tackle corruption and to treat fairly populations subjugated by the Romans. 
Religion & Beliefs
Vestal Virgins, were priestesses of Vesta, goddess of the hearth. Vestals were committed to the priestesshood before puberty (when 6–10 years old) and sworn to celibacy for a period of 30 years. They typically choosen among the ranks of the Roman elite (originally only among patrician families). They were so sacred and revered that everyone would give way to them in the street, including tribunes, consuls, and even the emperor, and death was the penalty for injuring one of them. The Vestals were considered of incorruptible character and their word being trusted without question. They had the power to free any condemned person on the spot simply by touching them. Vestals also had reserved place of honour at public games and performances.
Roman religion was polytheistic and very accommodating towards other religions. Foreign gods were readily incorporated to the Roman pantheon. Some of the most popular deities venerated by the Romans in Imperial times were the Egyptian goddess Isis and the Zoroastrian god Mithra. In contrast, the exclusive and intolerant nature of Christianity clashed in a irreconcilable manner with traditional Roman values and beliefs.
In contrast to Christianity, which places more value upon individual piety and prayer, Roman religion was strongly communal. Personal expressions of belief were less significant than participation in shared rituals, from private household ceremonies to state festivals, which appealed to the gods for the collective good. This is why high-ranking magistrates typically conducted religious ceremonies. Although the Romans lacked a distinct religious caste, the vast majority of Roman priests were men from the senatorial elite and of patrician descent. Julius Caesar himself was pontifex maximus, or chief high priest of Rome, and the position became the prerogative of emperors starting with Augustus. 
The Romans practised a sort of cult of ancestors in which wax masks of a deceased family member was displayed on the funerary urn. Spoils taken from the enemy were attached to their doors and not even a subsequent purchaser of the house was allowed to take these down. 
Roman society and mores completely changed with the advent of Christianity. Already in 206, the Christian writer Tertullian was urging women to wear veils and forsake any form of adornment. He openly criticised the theatre, public games and the baths, which had all been defining elements of Roman culture for centuries. In 380, Emperor Theodosius I made Christianity the Empire's state religion and in the following years banned classical sculptures of pagan deities, blood sacrifices (of animals), extinguished the eternal flame of the Temple of Vesta and and dissolved the Order of the Vestal Virgins in Rome, thus doing away with many integral parts of Roman religion. He even banned the Olympics in Ancient Greece, on the ground that they were decadent and involved immodest semi-nudity. Theodosius also encouraged the dismantling of pagan temples by Christian monks and ordered the destruction of the Serapeum of Alexandria, the successor of the Great Library, a tragedic loss of human knowledge recounted in the 2010 movie Agora. 
Society, Culture & Lifestyle
Ancient Romans also divided the day into 24 hours. However, contrarily to us, these hours did not have a fixed length, but varied with the seasons. There were 12 hours of light (horae) and 12 hours of darkness (horae noctis), meaning that, at the latitude of Rome, one hour was only about 45 minutes on the winter solstice, but about 75 minutes on the summer solstice. Noon was known as the sixth hour (hora sexta).
Roman society was originally regulated by the mos maiorum ("way of the ancestors"), a set of traditional social norms that affected private, political, and military life in ancient Rome. Its core values were fides (trust, good faith, reliability), pietas (dutiful respect towards the gods, homeland and family), religio & cultus (correct performance of religious rituals), virtus (valour, courage, manliness), disciplina (education, training, discipline), gravitas (dignified self-control), constantia (perseverance in the face of adversity), dignitas (reputation, honour) and auctoritas (prestige and respect).
The Romans greeted each others with a kiss on the cheek, a tradition that survives in Romance-language countries today, as well as in other parts of central and eastern Europe and in the Middle East. On the other hand, it was strongly frowned upon for lovers to kiss each others on the mouth in public.
In ancient Rome lovers did not dine in restaurants as is done today, and men didn't express their love by gifting flowers to their sweetheart. These symbols of romance now strongly associated with Italy evolved much later. The most common presents a (wealthy) man would purchase for his wife are expensive clothes and jewellery.
The Romans had a law that made it compulsory for a wife to kiss her husband on the mouth at least once a day! This law was called ius osculi. The purpose was for the husband to find out if his wife had drunk alcohol, which the Romans thought would cause a woman to lose control over her passions and would consequently cause her to cheat on her husband. If a Roman man discovered that his wife had committed adultery or even just drunk wine in his absence, he had the right to kill her. Over time the mores evolved so that the husband would simply repudiate or divorce his wife instead. 
Most marriages between wealthy Romans were arranged, often from childhood. Women were supposed to remain virgins until they got married. Young men were, on the contrary, encouraged to have sex with slaves or prostitutes before marriage.
The Western tradition of exchanging rings at the wedding and placing the ring on the left ring finger originated in Greco-Roman culture. On the other hand, weddings always took place at the bride's family home. The bride wore a white gown and a laurel wreath on top of which was placed a long red veil covering most of the body.
Ancient Romans believed that nerves carried not only physical sensations, but also emotions. Love was associated with the heart, which they believed was connected by a nerve to the ring finger - hence its designated spot for the wedding ring. 
For married Romans, having sex with someone of a lower social status, such as a slave, a freed slave or a prostitute (male or female), was not considered adultery or cheating. 
Roman women were expected to stay at home all day and take care of the household and children. Wealthy Roman girls and women in particular could not even go out of the house without supervision from a parent, a nanny, or a servant.
While originally the Roman woman was subordinated to the authority of the father, then husband, from the 1st century BCE they acquired near parity in status and freedom with men. One reason is that they were allowed to inherit property. Another was that they were well educated. 
Divorcing was extremely easily in Roman times. One of the spouses only needed to declared that the marriage was over in front of a few witnesses, and that was it, even if the other spouse didn't agree. Interestingly, women had the same power as men in this regard. However women were prohibited from re-marrying until one year after the divorce. 
Ancient Romans didn't categorise sex as heterosexual, homosexual or bisexual. It was just sex and there were no taboos regarding homosexuality. The Romans had sexual taboos nonetheless, and the most potent among them was that the person of the higher social status had to be dominant during sex. Between a man and a woman of equal level, such as spouses, the man had to assume the dominant role. Dominance was very important for the Romans, and the upper-class man imperatively had to take the dominant role in sex. A free man could have sex with a male slave as long as he was in the dominant role, but never the other way round. 
The Roman system of inheritance was not based on primogeniture. There was no presumption in Roman law that the firstborn son would be the sole or main heir. 
In Imperial times, when Rome was cramped by overpopulation, no ordinary citizen would bake bread at home for fear of starting a fire in the highly flammable apartment blocks. Instead, the poor would take their grain to bakers, who would make bread for them for a small fee. 
The Roman toga was a male attire, usually worn by the upper classes. Prostitutes were the only women in Rome who wear togas (as they were easy to undo).
A toga worn for a special occasion could be whitened with Cimolus earth to give it a pearly lustre. This was known as a toga candida (from candidus meaning white). Politicians standing for public office were known to wear such togas, which is why they became known as ‘candidates’.
The condition of slaves in Roman society evolved a lot over time. During the Republic slaves were simple "talking objects" with no rights, who could be abused or killed at will by their masters. During the Imperial period, slavery became seen as an unnatural condition and slaves were seen as humans like anyone else, thus acquiring some rights. A master who treated barbarically his slaves could now be forced to sell them, and a master who abandoned a sick slave so as to save the cost of medical treatment would be considered to have performed manumission by neglect. If the slave recovered, he or she became free. 
Domestic slaves were often well treated, sometimes to the point of being seen as members of the household. Under the rule of Augustus, so many wealthy Romans chose to give freedom to their slaves that the Senate had to set limits to the number of slaves that could be freed in one time (the Lex Aelia Sentia and Lex Fufia Caninia). The Lex Aelia Sentia decreed that "slaves who have been placed in chains by their masters, or have been branded, or have been subjected to torture for some offence and convicted, or have been delivered up to fight with others or with wild beasts, or to contend with gladiators, or have been thrown into prison and have afterwards been manumitted by the same, or by another master, shall become free, and belong to the same class as that of enemies who have surrendered at discretion". 
In Imperial Rome, slaves were allowed to run businesses and have slaves of their own. There was an entire body of commercial law stipulating what masters are liable for if a business enterprise run by a slave goes wrong, and what kinds of contracts a slave could sign on his master's behalf without the master even knowing about it. 
Unlike the Greeks or other ancient states, the Romans regularly freed a lot of slaves and allowed them to gain some (not all) of the benefits of citizenship. These liberti (freedmen) were expected to remain loyal to their former masters. In Imperial times some exceptional freedmen rose to positions of great wealth and power. 
Gladiators were generally slaves, condemned criminals or prisoners of war, although free people could choose to become gladiators for the money (quaestus causa) or seeking fame (virtus causa). This could be former soldiers who had gone broke or got a dishonorable discharge without pension, or people heavily indebted seeking a way to repay their creditors. Such voluntary gladiators would get paid about 4,000 sestertii for four or five years of service. 
Gladiators were at the very bottom of the Roman social hierarchy, below actors and prostitutes.
Gladiatoral games have their origins in the Etruscan culture. The Etruscans sacrificed human beings - such as prisoners of war - to the spirits of the deceased. The first attested arenas for combats of gladiators were built in Campania, such as in the city of Capua, which was founded by the Etruscans. Capua came under the protection of Rome in 338 BCE and was linked to Rome by the Via Appia in 318 BCE. In 264 BCE, the first recorded gladiator bout took place in Rome as part of funeral rites held by Decimus Iunius Brutus in honour to his deceased father. In 206 BCE, Scipio Africanus holds the first gladiatoral games outside funerals, although still in honour of his deceased father and uncle, who had died many years earlier. It is only from the 2nd century BCE that gladiator fights became used more widely for celebrations, then for entertainment. The first state-sponsored games for the public were held in 42 BCE, two years after Julius Caesar's assassination, as a way to appease the populace during the ensuing civil war. 
Gladiators trained in a gladiator school called ludus, owned by a lanista. From the time they joined the ludus, it tooks several months of hard training before a gladiator was ready to fight in the arena. As purchasing, feeding and training gladiators was expensive for the lanista, which made them expensive for the magistrates who purchased them for the games. The organisers had no interest in having the gladiators killed in combat, as they could not sell them back to the lanista afterwards. That is why the average fatality rate was only 5%. The main purpose of gladiatorial duels was to display the martial skills so praised by the Romans and typically ended when one fighter was wounded. Fights to the death were banned everywhere except Rome from circa 70 CE, and even in Rome they were rare occurrences, being staged only when the emperor was in attendance. 
Originally gladiator games were hosted in temporary venues without seating, like in the forum, as Republican Romans thought it decadent to sit while watching a fight. The oldest arena built in stone was erected in Capua in 70 BCE. The first permanent arena in Rome was built in 55 BCE by Pompey the Great. 
The golden age of gladiatorial games was roughly from 70 to 195 CE. Some of the grandest games ever held include:
The regular games held by emperor Domitian (reigned 81-96 CE) which introduced innovations such as naval contests, nighttime battles, and female and dwarf gladiator fights.
The 123 days of games at the Colosseum organised by emperor Trajan in 107 CE to celebrate his victory over the Dacians. They were the longest games ever held and featured fights of over 5000 pairs of gladiators.
The magnificent series of games held by emperor Antoninus Pius in 147 CE celebrating the 900th anniversary of the founding of Rome.
The Plebeian Games held by emperor Commodus in November 192 CE, in which the emperor himself fought as a gladiator - something absolutely outrageous and scandalous to the Roman aristocracy considering the reviled status of gladiators. This led to Commodus's assassination the next month.
The Ludi saeculares (Secular Games) organised by emperor Philip in 247 CE for the one thousandth anniversary of the foundation of Rome, in which more than 1,000 gladiators were killed.
Not all emperors were fond of gladiator fights. Tiberius banned them during his reign, whereas Marcus Aurelius, who disliked the sight of blood, made fighters use wooden or blunt swords.
In the first century CE, amphitheatres were built in all major cities of the empire to hold gladiatorial games, and by the rule of Emperor Trajan there were over 200 of them. The largest was the Flavian Amphitheatre in Rome, now known as the Colosseum, constructed between 70 and 80 CE by emperors Vespasian and Titus and which could host 50,000 spectators. Other notable amphitheatres include those of Capua near Naples (40,000 spectators, built c. 100 CE), Pozzuoli near Naples (40,000 spectators, built c. 60-100 CE), El Djem in Tunisia (35,000 spectators, built c. 238 CE), Tours in France (34,000 spectators, built 30 CE, expanded later), Verona in Italy (30,000 spectators, built in 30 CE), Carthage in Tunisia (30,000 spectators, built c. 100 CE), Pula in Croatia (26,000 spectators, built in 68 CE), Italica in Spain (25,000 spectators), Nîmes in France (24,000 spectators, built in 70 CE), Arles in France (20,000 spectators, built in 90 CE), and Pompeii near Naples (20,000 spectators, built in 70 BCE).
The Circus Maximus is the largest stadium ever built by mankind anywhere in the world. It was 640 metres (2100 feet) long and 150 metres (490 feet) wide and occupied an area of 45,000 m² (485,000 sq.ft), which is to say 12 times larger than the Colosseum. Each row of seat ran for 1450 metres (4750 ft) around the stadium. 
Modern historians have calculated that the Circus Maximus had a minimum capacity of 150,000 spectators, but Pliny the Elder mentions 250,000 spectators. During the Late Imperial period, some ancient authors have claimed that it could hold 480,000 people, although this is probably an exaggeration. In comparison, the biggest modern stadium is the Michigan Stadium – with an official capacity is 107,601. 
Chariot races were held on the location of the Circus Maximus, between the Palatine and Aventine hills, since approximately 600 BCE, when the fifth king of Rome Tarquin the Elder staged the first races, until 549 CE, under the reign of Gothic king Totila. With nearly 12 centuries of uninterrupted activity, the Circus Maximus holds the record of the longest lasting event venue in history. 
The arcades lining the Circus were dotted with all kinds of shops selling take-away food (bread, cheese, olives, fish), cushions, parasols, raincoats, but also ceramic and copper goods, statuettes, and so on. It was one of the busiest shopping area in ancient Rome. 
Although the Circus is most famous for staging chariot races, it was originally designed to host all kinds of events, including public feasts, theatrical performance, recitals, athletics, horse races, beast-hunts (venatio) and gladiator fights. Before being built in masonry, the Circus had a 3-metre wide moat surrounding the arena's ground to prevent wild animals from attacking spectators. The Colosseum was only inaugurated in 80 CE, almost 700 years after the first events in the Circus. More than any arena or theatre, the Circus Maximus was the focal point of entertainment throughout the history of ancient Rome. 
Entry to the Circus was free and despite its huge capacity the populace started queuing before dawn, or sometimes even the night before events were held to get the best seats. The front rows were reserved for the senators, equites, Vesta priestesses, and other important people. 
A second Circus Maximus was built in Byzantium in 203 CE by the Emperor Septimius Severus. In 330 CE Emperor Constantine moved the Roman Empire's capital to the city, which he renamed after himself and greatly enlarged. The enlarged Hippodrome of Constantine was about 450 m (1,476 ft) long and 130 m (427 ft) wide and had a capacity of 100,000 spectators.
Money & Trade
The Romans used gold, silver, bronze, orichalcum (golden colored copper-alloy similar to brass) and copper coins as their currency. These came in various denominations, which evolved over time. The base denomination during the late Republic was the as (sometimes also called assarius), a bronze then copper coin introduced in ca. 280 BCE. Denominations larger than the as were, in gradual order, the dupondius ("two-pounder", a brass coin worth two asses), the sestertius (or sesterce, a small, silver coin worth two and a half asses), the denarius (a silver coin introduced in 211 BCE and which name derives from the Latin deni "containing ten", and worth 10 asses), and from 23 BCE also the aureus (a gold coin worth 25 denarii). Coins less valuable than the as included the semis ("half" an assarius), triens ("a third"), quadrans ("a quarter") and uncia ("a twelfth").
The denarius gave its name to the term for "money" in Italian (denaro), Slovene (denar), Spanish (dinero) and Portuguese (dinheiro), but also to the dinar, the modern currency of Serbia, North Macedonia, Algeria, Tunisia, Libya, Jordan, Iraq, Kuwait and Barhain, and until the 20th century was also the name of the currency in Yugoslavia, Croatia, Bosnia and Herzegovina, Iran, South Yemen and Sudan. The denarius was also used in the Carolingian empire and survived in France under the name denier until the French Revolution.
Around the time of the late Republic and early Empire, one sesterce was worth somewhere between 1 and 2 $/€ based on the present-day (and fluctuating) value of gold, silver and copper. A loaf of bread cost roughly half a sesterce, a litre of wine from 0.5 to 2 sesterces, a tunic 15 sesterces, a donkey or mule 500 sesterces. An unskilled laborer earned ~800 sesterces per annum, while an artisan or an ordinary legionary would make between 1000 and 1500 sesterces. A centurion of average ranked made 20,000 sesterces/year. Magistrates earned at least 50,000 sesterces/year. The price of a domestic slave ranged anywhere from 500 to 8000 sesterces, depending on their age, looks, health, background, skills, etc.
The richest Romans were the senatorial class, who during the Late Republic had to be worth at least 400,000 sesterces, the same as the equites. When Augustus reformed the senate during the first years of the Principate, he raised the property requirement to 1,000,000 sesterces. During the Republic, the lowest social class, known as proletarii, had possessions below 11,000 asses (4,400 sesterces).
Traditionally, Roman coins depicted deities and personifications on one side and typically a horse rider or the prow of a ship on the other side. Gaius Julius Caesar was the first living person whose portrait featured on Roman coinage, and emperors from Augustus perpetuated that practice.
The Mediterranean Sea acted as a superhighway for trade within the Roman Empire. Transporting goods by sea was many times cheaper than by river or land, so much so in fact that it cost less to import grain from Egypt by sea than to trek it over the Apennines from the Po valley in Northern Italy.
Trajan's Market was the world's first known shopping centre. It was built under the suprevision of the great architect Apollodorus of Damascus between 107 and 110 CE on the Via dei Fori Imperiali, at the opposite end to the Colosseum. Covering some 60,000 m² (648,800 ft²), the multi-storied brick structure contained 150 shops, warehouses, restaurants, administrative offices as well as a library and performance halls. It also housed the Cura Annonae, a corn dole which provided 200,000 poor Romans with grain or bread at a price below market rates or for free. The large semi-cicrular complex still stands today in relatively good condition.
Population & Household
The Romans built condominiums (from Latin con + dominium, "shared ownership" or "common housing"), which they called insulae. These apartment buildings typically rose to 6 or 7 storeys and their height in fact became limited by law by Augustus (to 20.7 m) and again by Nero (to 17.75 m) after the Great Fire of Rome as safety precautions. In the 4th century there were 42,000–46,000 insulae in Rome, housing the vast majority of the population. Only the wealthiest 1% of the population could afford a house (domus). As the risk of fire was always present in ancient Rome, the most expensive apartments were located on lower floors, where people could escape more easily, and prices decreased as the floors rose, with the very poorest living under the roofs.
The townhouses of wealthy Roman, known as domus, typically lacked windows on the street side and instead got their light source from the open courtyards. The Romans combined the concepts of the Etruscan atrium and Hellenistic peristyle house. The atrium was the focal point of the domus, the most lavishly-furnished room, and contained a statue of or an altar to the household gods. The peristyle was a colonnated porch surrounding the perimeter of an inner courtyard or garden. The Roman peristyle was later refashioned as the cloister in medieval monasteries and survived in the patios of modern Andalusian houses.
Although the Romans did not invent plumbing or toilets, which they borrowed from the Greeks, their use of aqueducts allowed them to develop the most extensive and efficient sanitation system the world had ever seen, and which would only be equalled again in the late 19th century. In addition to having public toilets that flushed, the Romans enjoyed going to the public baths (thermae), used by the rich and the poor alike to wash themselves, performed exercises, sweat (in the caldarium or sauna) and relax.
During its heyday in the 1st and 2nd century CE, the population of ancient Rome was at least 750,000, possibly up to one million inhabitants, making it the largest city the world had ever known. In comparison, The largest Chinese city at the time, Chang'an, had a population comprised between 200,000 and 400,000 (it reached 1 million people circa 750 CE).
The life expectancy of the average Roman was about 25 to 35 depending on the century. This may appear extremely low, but this was mostly due to high child mortality and slavery. The life expectancy of a child who made it to the age of 10 was between 40 and 50 years old. Social class was also a major determinant, as the rich often lived well into their 60's or 70's (both Augustus and Tiberius died at 77 years old), if not longer, while slaves working on farms or in mines did indeed die young.
Out of 70 Roman emperors between 27 BCE and the division the empire in 395 CE, only 20 (28.5%) died of natural causes. The other were assassinated, executed, killed in battle or committed suicide.
Roman Inventions, Engineering & Technology
The Romans invented many technologies and systems that are changed the world and are still in use nowadays, including concrete, the cupola, the arch, aqueducts, Roman numerals, Latin script, bound books (made of animal skin parchment), the first newspaper (the Acta Diurna), the Julian Calendar (with the modern names of the month) and Welfare (e.g. subsidised food and education, including the Lex Frumentaria and the Cura Annonae). In addition, the Roman Law has influenced the development of modern legal system in Western countries, particularly in Romance-language countries. In English, legal terms such as affidavit, habeas corpus, plebiscite, pro bono and subpoena, among others, all have a Roman origin.
A common misconception is that Romans designated spaces called vomitoria for the purpose of actual vomiting during the orgies (one of the numerous fallacies conveyed by the French comics Asterix). A vomitorium was in fact a passage situated below or behind a tier of seats in an amphitheatre, through which large crowds could exit rapidly at the end of a performance, as they do in modern sports stadiums.
The Romans were master road builders. At the peak of Rome's development, 29 great military highways radiated from the capital, and during the late Empire the 113 provinces were interconnected by 372 great roads. The whole comprised more than 400,000 kilometres (250,000 miles) of roads, of which over 80,500 km (50,000 mi) were stone-paved.
Roman roads were so technologically advanced that many have survived to this day and their quality would not be rivaled until the Modern Age. They were made by digging a trench of a depth of up to 2 metres, which would be filled by three layers of gravel, coarse concrete and fine cement, topped by a fourth layer of rectangular blocks of travertine paving. This system of stratification allowed water to drain through the road like in a filter. A slightly convex curvature of the road took away the water that didn't pass through, so as to prevent the formation of puddles that would corrode the stone pavement. Roman engineers cut through the landscape to keep roads as straight as possible and to maintain a slope of maximum 8 or 9% to assure that horse-drawn carriages could ascend and descend safely. The convex road for carriages was lined by a flat and elevated sidewalk for pedestrians (including legionaries). In the mountains, roads were equipped with wheel-tracks to prevent carriages from slipping off the cliff. 
The network of Roman roads that crisscrossed the empire was mainly designed to carry troops swiftly where they were needed. But they also facilitated the transport of goods, the migration of people and the diffusion of culture and ideas, creating a diverse, multi-ethnic and dynamic society. Unlike the Phoenicians/Carthaginians and the Greeks who propagated their colonies solely through maritime routes, the Romans unified their empire from the land as well as the sea, bringing about the first globalisation in history. 
The Romans called their roads via strata ("layered road"), from which the Italian strada, the Romanian stradă, the English street, the Dutch straat and the German Straße are derived.
Changing stations, known as mutationes were located every 20 to 30 kilometres (12 to 19 mi) along Roman roads. In these complexes, the driver could purchase the services of wheelwrights, cartwrights, and horse veterinarians. Approximately every few mutationes, travellers would encounter a mansio, which not not only changed horses, but also had an inn (cauponae) to eat and stay for the night.
Emperor Augustus established Europe's first official postal service, known as the cursus publicus (fast course), using the extensive Roman road network. Horse-drawn mail carts could travel at least 80 km (50 mi) a day, and relay teams delivering urgent messages from the emperor could cover over 275 km (170 mi) per day.
It has been argued that the main reason why the ancient Romans did not become a fully mechanized culture is due to the abundance of cheap manpower available. Some ingenious and labour-saving inventions were not used for this very reason.
Roman Army & Warfare
Roman military technology evolved a lot during the 1000 years of Republic and Empire. In the early days of the Republic, Roman soldiers possessed quite similar equipment to the Gauls and other Celtic tribes, to which they were genetically, linguistically and culturally related. Both carried colourfully decorated oblong shields, a simple round helmet (see Coolus helmet and Montefortino helmet), and a relatively long sword and/or a spear. During the Late Republic and Early Empire, the legionary's equipment would be standardised, with shields becoming broader, rectangular and curved, swords getting shorter with the adoption of the gladius hispaniensis (borrowed from the Celtiberians in the the 3rd century BCE) and the spear (hasta) was abandoned to be replaced by various types of javelins (pilum, verutum and lancea). The Imperial helmet worn by Roman legionaries from the mid 1st century CE came into two subtypes: the well-known "Imperial Gallic", crafted by Gauls, and the "Imperial Italic", a less-skilled copy produced in Italy and elsewhere in the Empire.
Originally, to be eligible to become a Roman soldier one had to be a free Roman citizen who owned property worth at least 3500 sesterces in value and could supply their own armaments. There was no professional army. Instead most soldiers were farmers who joined the militia in time of war, then return to till their fields once the war was over. The Marian reforms of 107 BCE changed all this with the establishment of a true professional infantry army. With these reforms, soldiers became paid by their generals and consequently armies became personal, loyal to their general rather than to the Senate or the Roman state.
The Roman legion (legio in Latin, originally meaning 'levy') referred to the part of the army raised among Roman citizens. Over time, as the numbers of citizens grew, each consul was given his own legion and by the third century BCE it was normal for them to command an army of two legions. The legion had become the most important unit of the army. It varied in size from at least 4,000 men to more than 5,000, reflecting senatorial opinion of the scale of the military problem. During the Mid-Republic (338-88 BCE), each legion was normally supported by a similarly sized ala, a wing of allied troops, which would deploy on either side of the legions. 
During the late Republic, at least half of the Roman army consisted of allied soldiers, and that proportion was often considerably higher, up to two-thirds of the total. 
The size of the Roman army varied over time, but was always substantial from the 3rd century BCE. The Greek historian Polybius states that in 225 BCE there were 250,000 Roman citizens eligible to serve as infantry and 23,000 as cavalry. Adding their Latin and other allies, the total numbers that could theoretically be called upon by the Roman Republic were a staggering 700,000 foot soldiers and 70,000 cavalry. Under Augustus (27 BCE-14 CE) the Roman army numbered 250,000 foot soldiers equally split between 25 legions and 250 units of auxiliaries. The numbers grew to a peak of about 450,000 by 211 CE, in 33 legions and about 400 auxiliary units. In the 4th century, the Roman army contained perhaps as many as 600,000 soldiers. 
In many parts of the empire, including Egypt and Britain, Roman soldiers had higher literacy level than the local population and as such they became the principal engine of Romanisation. 
Here are the modern European cities of over 50,000 inhabitants that were founded (or re-founded) by the Romans. Those in bold have a population of over 500,000 today. Those marked by an asterisk had the status of colonia
In Britain : London, Dover, Canterbury, Gloucester*, Winchester, Chichester, Southampton, St Albans, Colchester*, Cambridge, Lincoln*, Leicester, Leeds, York*, Manchester, Chester, Newcastle upon Tyne.
In the Benelux : Tournai, Tongeren, Maastricht, Heerlen, Nijmegen, Utrecht, Leiden, Katwijk, Alphen aan den Rijn.
In France : Paris, Beauvais, Amiens, Boulogne-sur-Mer, Orléans, Narbonne*, Arles*, Orange*, Lyon*, Besançon, Metz, Strasbourg.
In the former Austro-Hungarian Empire : Salzburg, Linz, Vienna, Szombathely*, Budapest, Szeged, Bratislava, Ljubljana*, Pula*, Zagreb, Osijek, Sisak, Dubrovnik, Drobeta-Turnu Severin*, Cluj-Napoca*, Alba Iulia*.
In Italy : Rome*, Salerno, Florence, Pistoia, Forlì, Rimini*, Bologna*, Reggio Emilia, Piacenza*, Massa, Monza, Turin, Aosta, Bolzano, Belluno, Venice.
In Iberia : Braga, Coimbra, Mérida*, Cordoba*, Seville*, La Coruña*, Lugo, Santander, León, Avila, Segovia, Zaragoza*, Valencia, Tarragona*, Barcelona, Girona.