Korean: there are three Chinese characters for
the Korean surname To. Of these, two are quite rare, while the
third is used by at least fifteen clans. Three clans can be
documented, but two of them appear to be practically extinct. Only the
Söngju To clan has a significant population in Korea. The origins
of the Söngju To clan are unclear. It is certain, however, that the
clan was living in the Söngju area by the end of the post-Shilla
Three Kingdom period.