 Complete the following phrase:  The first traces of civilization in Bileća date from the Neolithic period, although archaeological sites are insufficiently explored. The first written documentation of Bileća as an inhabited place can be found in Ragusan documents dating from 1286, when it is mentioned under the name Bilechia. Bileća is mentioned in the 14th and 15th century as an important cross road town in caravan routes. It became a part of the Bosnian state for the first time in 1373, after the defeat of Nikola Altomanović. A document dated 8 September 1388, mentions that the army of duke Vlatko Vuković defeated the Turkish army at the 