@gyms So, what was the lanaguge of Hungarians in 10th century? Here it says:
"The oldest rune-shaped inscription in Hungary dates from the 9th and 10th centuries CE, but these earliest texts are poorly understood and maybe even not in the Hungarian language but perhaps in an unidentified Turkic dialect."
http://www.ancientscripts.com/old_hungarian.html
Epigraphic evidence for the use of the Old Hungarian script in medieval Hungary dates to the 10th century, for example, from Homokmégy[11] The latter inscription was found on a fragment of a quiver made of bone. Although there have been several attempts to interpret it, the meaning of it is still unclear.
In 1000, with the coronation of Stephen I of Hungary, Hungary (previously an alliance of mostly nomadic tribes) became a Kingdom. The Latin alphabet was adopted as official script, however Old Hungarian continued to be used in the vernacular.
http://en.wikipedia.org/wiki/Old_Hungarian_alphabet
The hungarian conquerors where supposedly bilingual.
http://en.wikipedia.org/wiki/Hungarian_conquest_of_the_Carpathian_Basin
http://scienceblogs.com/gnxp/2007/07/18/who-were-the-ancient-hungarian/