The fortress is the main stronghold of the defence system of a medieval town. It was built in the period between the 13th and the first half of the 14th century. The most famous ruler of the medieval town of Jajce was the duke Hrvoje Vukcic Hrvatinic at the turn of the 14th and the 15th centuries.
In the mid 15th century, the royal court moved in to Jajce, when a palace was built within the fortress. A biphora remained in bastion II, where quite possibly a dwelling place of the feudal lord was placed.
At the southern wall of the fortress is "the roaly portal " that was opened some time around 15th century.