 They were actively meddling in medieval Bosnian affairs since early 1400s and had a permanent garrison stationed in Vrhbosna as early as 1414.However, as it was typical of the fickle politics in High Middle Ages in Europe, Bosnians gladly accepted Ottoman help this time in order to hit back at Hungarians which were incessantly waging wars and Crusades against them for the better part of last two centuries.After careful positioning on the battlefield, the heavy cavalry charge opened the battle, with the smaller pockets of close quarter fighting subsequently developing on gentle slopes of the area set amidst rivers Bosna and Usora.