Kossakowski (Lithuanian: Kosakovskiai)[a] was an aristocratic family of Mazovian origin.[1][2]
They were first mentioned in the 13th century and initially settled in Ciechanów County, from where they branched out to the Grand Duchy of Lithuania, Podolia, Volhynia, and Livonia.[1]
Coat of arms of the Kossakowski family was Ślepowron.