The Hungarian ethnic group lives on the fertile fields of the central part of Donau River and it’s tributaries. Politically this is a dangerous area criss-crossed in ancient times by migrating ethnic groups, fought over and raided through the centuries by neighbours and marauders from afar seeking loot and slaves. The northern border of the Roman Empire ran along Donau River for centuries with the subsequent settlement of veteran soldiers along the border as a bulwark of faithful military trained subjects ready to defend their newly acquired farms and Rome against all invaders. Atilla the Hun had his camp in this area and later on Uralic-speaking confederacy of tribes originally from the area between Ob and Yenisai rivers in the Ural Mts. between Europe and Asia, settled there and imposed their language on the local population. Among the confederation were not only tribes that spoke the dominant Uralic language but also an Iranian-speaking group of Ossetians called Jász. Although the Uralic identity and language had a long lasting effect on present day Hungarians, very little remains of their genetic legacy. All these historic events has effected the DNA of the people that call themselves Magyars.
Hungarian DNA as it appears in y-dna haplogroups gives the results of a highly mixed population. Historically the Hungarians and the plains they inhabit, has been a contested area for millennia. This historic lack of peace and tranquility is seen in the number of haplogroups found in Hungarians. At least one of the most common, I2, is ancient and probably represents the indigenous inhabitants. Interestingly, one of the smaller ones, haplogroup G, likely represents the first agriculturalists and/or metal smelters of iron, spreading out from the Caucasus Mountains. Some of the minor ones were likely introduced into the area during the Greek and Roman period, like haplogroups E and J2. One of the two main ones and more recently introduced, haplogroup R1a, is a result of a massive wave of Slavic-speakers immigrating into the area from north and west.
Neighbouring haplogroups that dominate the surrounding area is to the west, R1b in Austria, are a mixed people of Celtic and Germanic descent. North and northeast are Slavic groups were R1a dominates. South is another grouping of Slavic-speakers but here I2 dominates. In that area the language is the legacy of a Slavic conquest of the Balkans after the Roman Empire collapsed.
It is clear from looking at the map of the distribution of haplogroups in the Donau River Valley, that geographic features are a greater factor in determining their frequencies than political or linguistic ones. Here I am talking about the Donau River itself as it flows from north to south. The dominating haplogroups are different west and east of the river. Still, Hungarians on both sides of the river have the same language and ethnic identity as Magyars.
It proves yet again how fluid the ethnic construct can be. Remembering the past is not one of humanities strongest qualities. Thus we are forever doomed to repeat our mistakes. In time new groupings come into existence with new ideas of their reality. A new society is created and culture constructed by mixing the old with new. But, as further we get from our historic origin, the closer we get to mythical ideas cemented with a good dose of imagination. Religions come into existence with a full set of one or more imaginary friends. This along with idealized history, language, politics based on love, hate and greed, and interaction with others, create our true identity of self. The group we end up identifying with conforms most with what ideals and interest we think we have most in common with.
Conclusion: Hungarians are a mixed group of people, generally speaking. East and north of Donau River people are mostly related to Slavic-speakers of haplogroup R1a. West of Donau R. haplogroup R1b dominates of the Germanic/Celtic heritage. South is haplogroup I2 of the ancient Donau River Valley populations that have inhabited the fertile fields in central and lower Donau since before Celtic, Germanic and Slavic peoples arrived in this area. Interspersed among Hungarians, but more frequently west of Donau R., are low frequencies of haplogroups that originated in the eastern part of the Mediterranian and in Anatolia. These groups most likely arrived during Roman times as it was a military tradition to reward veteran soldiers from the legions with a piece of land somewhere on the border regions in the Empire. It was a smart move as these veterans were among the most loyal subjects that would defend both their land-holdings and the Empire more diligently than ordinary subjects in the Roman provinces.