Dub mac Maíl Coluim (died 967) was king of Alba. In older histories his name may be found anglicised as Duff; the modern Gaelic version is Dubh, which has the sense of dark or black, especially in reference to skin colour; in the Chronicle of the Kings of Alba and related Scoto-Latin texts he is called Niger ("Black"), a literal Latin translation of Dub. It may be that Dub was an epithet, as the Duan Albanach refers to him as Dubhoda dén, Dubod the vehement or impetuous. He was son of Máel Coluim mac Domnaill and succeeded to the throne when Ildulb mac Causantín was killed in 962.
See more at Wikipedia.org...