The Principality of Zeta is a medieval state ruled by the families of Balšić, Lazarević, Branković and Crnojević in succession from the second half of the fourteenth century until the Ottoman vassalage in 1514.

The Serbian crown land of Zeta had become virtually independent during the fall of the Serbian Empire, when Balša and his sons wrestled the region by eliminating Žarko in Lower Zeta (1360), and then Đuraš Ilijić in Upper Zeta (1362).