A medieval fortress in Bac is also known as one of the biggest fortresses of that time in Pannonia.It was built near the settlement of the same name on its west side and on asmall island that was made by the river Mostonga.The fortress in Bac belongs to the so called “water towns “ because it was completely surrounded by water and the only way to get to it was across a drawbridge.
The fortress has a pentagonl base with towers at each angle.Inside the walls of the fortress there is the tallest central tower (donjon or defender tower). This tower was an important part of a defence system of the fortress but also a watchtower.According to some chronicles Bac was also a Barbarian fortress (873. year) . Hungarian king Stjepan I founded a parish in Bac and at the end of the first and the beginning of the second millenium ,Bac has already beena built and fortified town connected to the Danube through the Mostonga river.During the reignof the Arpad dynasty, Bac became not only a church centre of the archbishopric but also a royal town where noblemen and rulers came to conferences ,gatherings and assemblies. In the 12th century Bac was flourishing . During that period a powerfull fortress is mentioned for the first time in written documents.It will survive several destructions and it still attracts many scientists and tourists .At the head of the parish of Bac were great bishops ,appointed by the king and they were rulers in this region before the Mongolians came in 1241.
They were collecting donations,appointing military and civil commanders .Since the 12th century it was a custom to offer hospitality to the King once a year.Except the parish administrator there were subadministrators, judges,military officers and others.At the beginning of the 14th century the dynasty has changed in Hungary and Charles Robert from the Anjoy family took over the power.In the period from 1338 to 1342, he built a town (fortress) on the river Mostonga with a square tower,six storeys high,important for the town defence system .Today it is the oldest medieval fortress in Vojvodina built by Peter Varadi (see Petrovaradin Fortress ,Novi Sad).The town had eight towers ,rooms for the parish administrator ,halls,rooms for the guards,kitchen,well,barn, etc. Lower from the town a civil settlement was growing and people could come to this part of the town called suburbs across a drawbridge through the gate called “Siljak” where once stood a wooden drawbridge very characteristic for that time .
The fortress was put out of use after the fire and destruction at the beginning of the 17th century during the battles between Austria and Rakotzy rebels from 1702-1704.