Bulgaria is named for the one founding people who contributed least to its genome. The Bulgars gave the state its name and its first dynasty; the language is Slavic; and the genetic base under both is the old population of Thrace, carried through Rome's Balkan provinces. Ancient DNA — with the Balkans now among Europe's best-sampled regions — can put rough weights on all three.
The short answer: Bulgarian ancestry is the Balkan deep stack — Thracian-era locals shaped by farmer, steppe and provincial-Roman layers — plus the early medieval East European (Slavic- era) addition the peninsula-wide transect measures at a large minority to roughly half by region. The Turkic Bulgars register as a small steppe trace at most. Modern Bulgarians sit centrally in the Balkan cluster, closest to North Macedonians, Romanians and Serbians.
Thrace, and the province#
The territory runs the Balkan deep sequence from the front row: Europe's first farming societies (Karanovo), spectacular Copper Age wealth (the Varna cemetery's gold, the oldest known), early steppe-derived arrivals across the Danube plain. By the Iron Age the land was Thracian — the Odrysian kingdom's world — and its sampled genomes carry the settled Balkan blend of farmer, steppe and local forager legacies, kin to the Daco-Getic north and the palaeo-Balkan west.
Rome made Thrace and Moesia core provinces, and the Balkan transect (Olalde et al. 2023) shows what provincial status meant genetically: continuous Anatolian and eastern-Mediterranean inflow through the imperial centuries — the same cosmopolitan drift measured across the frontier — over a persistent local base.
The two arrivals, weighed#
The early Middle Ages brought both founding arrivals within two generations of each other, and the genetics now separates them cleanly:
- The Slavic-era layer is large. The transect measures East European-related ancestry entering the Balkans at scale from the sixth century — in the eastern Balkans a large minority of ancestry, with regional values ranging toward half. In Bulgarian genomes it is the second pillar, fused with the provincial base — the same proxy-dependent figure every Balkan estimate carries.
- The Bulgar layer is thin. Sampled elite burials associated with the early khanate carry the expected mixed steppe profiles (Turkic-era Central Asian blends), but their contribution to the broader population reads as small — a ruling minority absorbed within centuries, the Hungarian conquerors' story with an earlier date and a linguistic twist: here the newcomers lost their language to the majority.
Ottoman centuries added regional texture (strongest in communities with documented conversion and settlement histories — the Pomaks read genetically as local Bulgarians, incidentally, not as settlers) without moving the national centre. Modern Bulgarian genomes sit centrally Balkan: closest to North Macedonians (near-identical in most panels), then Romanians, Serbians and northern Greeks. Y-DNA carries the balance sheet: E-V13 and J-L283's J2b kin for the palaeo-Balkan share, I2a-Dinaric and R1a for the Slavic-era one, R-Z93-adjacent traces for the steppe visitors.
Reading your own results#
- G25 distances: modern era led by Bulgarian and North Macedonian averages with the Balkan neighbourhood tight behind; expect near-ties — this is one of Europe's most compact regional clusters. Ancient eras: provincial-cosmopolitan company in Antiquity, Thracian- era Balkan samples deeper.
- Admixture fits: the Balkan two-source medieval structure (provincial base
- Slavic-related) is mandatory panel design here; collinear Balkan sources are the standing trap, and a small steppe-nomad component should be treated as noise unless formally tested.
- qpAdm: two crisp questions — what Slavic-era weight does my genome require? and does it need any Bulgar-like steppe source at all? The second usually answers no with a clean rejection, which is itself the historically interesting result.
Frequently asked questions#
Are Bulgarians Slavs or Bulgars genetically?#
Mostly neither-alone: the largest share is the old Balkan provincial base, the Slavic-era layer is the major addition, and the Bulgars are a trace. The name and the language each came from a different pillar than the plurality of the ancestry — the Balkans in one sentence.
How much Thracian ancestry do Bulgarians have?#
A substantial share via the provincial continuum — but "percent Thracian" is not a well-posed number: Thracians were themselves a blend, and later layers fused with theirs. Formal models can weigh era-sources; they cannot resurrect a census.
Are Bulgarians close to Turks genetically?#
Closer than politics suggests and further than geography might: Anatolian Turks carry the old Anatolian pool, Bulgarians the Balkan one — the two share deep Mediterranean-Anatolian layers while differing in the Slavic-era and Central Asian additions respectively.
Terms used here are defined in the glossary.
Sources and further reading#
- Olalde, I. et al. (2023). A genetic history of the Balkans from Roman frontier to Slavic migrations. Cell, 186, 5472–5485.
- Mathieson, I. et al. (2018). The genomic history of southeastern Europe. Nature, 555, 197–203.
- Lazaridis, I. et al. (2022). The genetic history of the Southern Arc. Science, 377, eabm4247.
