Doboj Fortress in Bosnia

In northern Bosnia, where Balkan mountains slowly fade into lowlands, in the 13th century, sprouted the fortress and borough of Doboj, thanks to, primarily, an extremely large value of communication crossings, created by nature and meetings of thee river valleys of Bosnia, Spreca and Usora. It is believed that the construction of the Doboj fortress began and lasted in the time period from 1250 to 1300. The medieval part of Gradina was built by the Kotromanics, and the surrounding wall was built by the Turks occupation of this area.

The Doboj fortress was mentioned the first time in a written document in 1415: "...in Usora suptus castrum Doboy...". This news was sent to the Hungarian king Sigismund by Dubrovnik merchants