[6] Sultan Mehmed II gathered an army of 150,000 soldiers in Adrianopolis and departed for the Lower Danube area in April 1463.

[7] As a part of a diversion attack, he commanded Ali Bey Mihaloğlu to invade southern lands of the Kingdom of Hungary.

He then made a flanking move to the heart of Hungary until he reached Temesvár, where he encountered John Pongrác Voivode of Transylvania and was defeated in a fierce battle.

The conquering Ottomans saw the significance this strategic location represented for the military, later developing and expanding the castle, transforming it into a fortress with watchtowers.

[9] During the period of the First World War, Travnik was behind the front lines and the fortress saw no action; however military activities were carried out within its walls.