Genetic study Medieval genomes from eastern Iberia illuminate the role of Morisco mass deportations in dismantling a long-standing genetic bridge with North Africa

[Tautalus]

This paper uses ancient DNA from 12 individuals across eastern Iberia, from late antiquity (Roman and Visigothic periods), through the Islamic era (Al-Andalus), to medieval and post-medieval Christian periods, to clarify how successive waves of migration changed the genetic landscape.
Even before the Islamic period, eastern Iberia had genetic mixing from various Mediterranean regions, including small amounts of North African ancestry. After the Islamic conquest, North African ancestry became more common, reflecting increased migration and social changes.
After the Christian reconquest, North African ancestry remained in some communities, showing lasting effects of earlier migrations.
The analysis identifies differentiated genetic profiles among groups such as Muladi (Christian converts to Islam), Mudéjar (Muslims living under Christian rule), and Morisco communities (Muslims forcibly converted to Christianity). Despite the Christian reconquest, North African ancestry persisted in parts of the local population until the seventeenth century. In the later period, there is a notable contrast: one post-medieval individual (GOG59) has much of his ancestry deriving from a North African-related source (with archaeological evidence like an iron shackle hinting at enslavement), whereas another (GOG60) has no traces of North African-related ancestry and aligns fully with modern Iberian genetic profiles. These differences are linked to historical events like the mass deportations of Moriscos in 1609 CE. That forced deportation drastically changed the population, reducing North African genetic contributions.
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Abstract
Background

The Islamic influence on the Iberian Peninsula left an enduring cultural and linguistic legacy. However, the demographic impact is less well understood. This study aims to explore the dynamics of gene flow and population structure in eastern Iberia from the early to late medieval period through ancient DNA.​

Results

Our comprehensive genomic analysis uncovers gene flow from various Mediterranean regions into Iberia before the Islamic period, supporting a pre-existing pan-Mediterranean homogenization phenomenon during the Roman Empire. North African ancestry is present but sporadic in late antiquity genomes but becomes consolidated during the Islamic period. We uncover one of the earliest dated Islamic burials in Spain, which shows high levels of consanguinity. For the first time, we also demonstrate the persistence of North African ancestry in a Christian cemetery until the seventeenth century, in addition to evidence of slave trafficking from North Africa.​

Conclusions

This study reveals the complex interaction between political events and cultural shifts that influenced the population of eastern Iberia. It highlights the existence of a slave trade, underscores the low impact of the Reconquista in the genetic landscape, and shows the lasting impact of post-medieval events, such as the Expulsion of the Moriscos in 1609 CE, on the region’s genetic and cultural landscape, through mass population displacement and replacement.
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Medieval genomes from eastern Iberia illuminate the role of Morisco mass deportations in dismantling a long-standing genetic bridge with North Africa - Genome Biology

Background The Islamic influence on the Iberian Peninsula left an enduring cultural and linguistic legacy. However, the demographic impact is less well understood. This study aims to explore the dynamics of gene flow and population structure in eastern Iberia from the early to late medieval...

genomebiology.biomedcentral.com

Admixture model

PCA plot

Haplogroups

LabID	Location	Period	mtDNA	chrY (Isogg 2019 ?)	chrY	Genetic Sex
GOG20	Vall d’Uixo	Islamic	J1c1b	-		XX
GOG23	Vall d’Uixo	Islamic	HV	E1b1b1b1a1	E-M81/E-M183	XY
GOG24	Vall d’Uixo	Islamic	U4a1d	J2a1b1	J-M260	XY
GOG25	Vall d’Uixo	Islamic	L3d1	-		XX
GOG26	Vall d’Uixo	Islamic	H1	-		XX
GOG34	Sanxo Llop	Visigothic	HV+16311 (HV34)	R1b1a1a2a1a1c2b2a1b4	R-L11	XY
GOG35	Sanxo Llop	Visigothic	H2a1e1a	-		XX
GOG50	Valencia	Late Roman	D4e1	-		XX
GOG56	Valencia	Late Medieval	H+7720	-		XX
GOG57	Valencia	Late Medieval	R0a4	-		XX
GOG59	Valencia	Post Medieval	H5+152	E1b1b1b1a1	E-M81/E-M183	XY
GOG60	Valencia	Post Medieval	K1a+195	R1b1a1a2	R-M269	XY