Fortress of Doboj

History

Built in the early 13th century on a site that held a clay and wood structure from the 10th or 11th century, Doboj Fortress was a key defense in the medieval banate or duchy of Usora. Its initial construction, lasting until about 1415, was in the Romanesque style. A major reconstruction in the spring of 1415 added Gothic elements and reinforced the large keep with walls up to 3 feet thick on the eastern side.

The northern tower gained a bastion with six cannon, and the captain's tower became a five-story donjon with a square base, unusual for Usora. Outer walls were built around the original triangular core, and three towers—Northern, Eastern, and Southern Gate—were strengthened. The Southern tower's walls were rounded to deflect cannonballs around the 1370s–1380s.

Local captains used cannons, bombards, and balistas from Dubrovnik. A permanent contingent was stationed there from the early 14th century, armed with swords, lances, halberds, bows, crossbows, and later handguns. Finer equipment came from Germany, Venice, and Dubrovnik, whose engineers also built the water cistern in the upper fort.