in 1217, serbian ruler, grand župan stefan the first-crowned was crowned the king of serbia by the papal legate. king andrew ii of hungary, angered by the fact that the ruler of serbia is now equal to him and considering serbia its vassal, decided to attack stefan. in 1220, andrew ii encamped at the location of modern kovilj, which at the time was the territory of hungary. saint sava, brother of stefan, arrived and began diplomatic talks to prevent the war and managed to reconcile two kings.