The Hungarian Grey (HG) cattle breed was almost extinct after WW2; only 200 cows and six bulls survived. Despite the historical significance of the HG, no comprehensive genomic analysis has been conducted to clarify its genetic diversity and evolutionary history. Previous studies have relied on random or limited pedigree sampling, lacking a fully representative dataset determining genetic and conservation status. Here, the founder sampling of 110 individuals and the analysis of their mitochondrial DNA (mtDNA) sequence variation aim to investigate the phylogenetic placement of the breed using, for the first time, a fully representative sample. All identified haplogroups belong to the taurine T macro-haplogroup, with a predominance of T3 (89.1%), followed by T2 (4.5%), T1 (3.6%), and T1′2′3 (2.7%). The phylogenetic analysis confirms the absence of ancient haplogroups derived from European aurochs, suggesting a purely taurine origin for the HG breed. The high haplotype diversity (Hd = 0.94) and the genetic similarity to other Podolian breeds, particularly Maremmana cattle, indicate a preserved genetic background despite centuries of selective breeding. The lack of intensive crossbreeding practices has maintained the original beef production purpose of the breed, distinguishing it from the crossbred Podolian cattle used for dual-purpose or dairy production.