Emperor Cao Cao was a cruel and merciless Chinese warlord, but also a brilliant ruler and military genius. He rose to power in the final years of the Eastern Han Dynasty and was posthumously honored as “Emperor Wu de Wei”.

Was Cao Cao’s father adopted from within his own clan?

Cao Cao’s grandfather was a eunuch known as Cao Teng. Historical documents suggest that Cao Teng’s son, Cao Song (Cao Cao’s father) was adopted from within his own clan. However, opponents of Cao Cao argued that Cao Cao had no right to be Emperor, because they claimed that his father (Cao Song) was adopted from beggardom.

Using genetics to trace the ancestry of Cao Cao

Previous genetic analyses of the descendants of Cao Cao had already determined that he belonged to the Y-DNA haplogroup O2*. Y-DNA is passed down from father to son along the direct paternal lineage; so all males who have descended from the same paternal lineage are expected to have exactly the same or very similar Y-DNA profiles. This means that if Cao Song was adopted from within his own clan, Cao Cao should share the same Y-DNA profile as his paternal granduncle, Cao Ding.

A partial Y-DNA STR profile (12 STR markers) was obtained from a tooth from the tomb of Cao Ding. This partial profile was associated with the highest probability of belonging to Y-DNA haplogroup O2*, indicating that the historical documents were correct and Cao Song was adopted from within his own clan.


The Y-DNA analyses conducted in this study confirmed that Cao Cao’s Y-DNA profile matches that of his paternal granduncle, Cao Ding. It was already known that Cao Cao’s father (Cao Song) was adopted by Cao Teng, but is was unknown whether this adoption was from within the family clan. We now know that Cao Teng did adopt from within his family clan (maybe from a brother or paternal uncle) and Cao Cao had every right to become the Emperor of the Eastern Han Dynasty.

DNA Database Comparisons

The DNA tests conducted in this study have defined the Y-DNA STR paternal line profile of Emperor Cao Cao. If you have taken the Y-DNA STR marker (Paternal Ancestry) test, you can compare your DNA against Emperor Cao Cao to see if you have descended from the same Cao clan.