Kosača noble family

The House of Kosača (Serbian Cyrillic: Косача, pl. Kosače / Косаче), somewhere Kosačić (Serbian Cyrillic: Косачић, pl. Kosačići / Косачићи), was a Bosnian medieval noble family which ruled over parts of modern-day Bosnia and Herzegovina, Croatia, Montenegro, and Serbia between the 14th century and the 15th century. The land they controlled was known as Humska zemlja (Hum, for short), roughly corresponding to modern region of Herzegovina, which itself was derived from the title "Herzog", which Stjepan Vukčić Kosača adopted in 1448., with latin title "Dux Sancti Sabbae". Besides Hum, they ruled parts of Dalmatia and Rascia. They were vassals to several states, including the Kingdom of Bosnia and Ottoman Empire. Historians think the Kosača family is part of the Kőszegi family (House of Herceg), but there is a lack of evidence for this claim.

The religious confession of the Kosača family is uncertain. They were in contact with the Eastern Orthodox Church, the Church of Bosnia, the Roman Catholic Church and Islam. During the fall of the Bosnian Kingdom, the "Kosače" split into three branches: Venetian, Dalmatian and Ottoman. From then onward, these branches became accepting of the Roman Catholic faith, in the first two cases, and of Islam in the third.