The castle was built on top of a steep hill dominating the surrounding terrain at 920 m altitude.

[1] In the early 15th century, Koznik belonged to Grand Čelnik Radič, one of the most important knights at that time.

Lazar's widow, Princess Milica spent some time there, in 1402, while their son, despot Stefan Lazarević, made two decrees in Koznik in 1405, granting Radič Postupović all surrounding villages and the church on the river Grabovničica.

[1] After a brief Ottoman conquest of Koznik, the castle returned to despot Đurađ Branković in 1444.

[1] Koznik Fortress was declared a Monument of Culture of Great Importance in 1979, and it is currently protected by the Government of Serbia.