Hungarian-Serbian War (c. 960)

According to the dubious late 13th century Chronicle of the Priest of Duklja, a Magyar leader named Kisa (Kiš) led an invasion into Bosnia, where he was decisively defeated by certain Ciaslavus somewhere on the Drina near a place called Civelino. Kisa's widow requested from the Magyar chief to give her another army to avenge his death. With an "unknown number" of troops, the widow went for Ciaslavus, encountering him somewhere in Syrmia. In the night, the Magyars attacked the Serbs, captured Ciaslavus and all of his male relatives. On the command of the widow, all of them were bound by their hands and feet and thrown into the Sava river. Seemingly the region of Syrmia wasn't conquered as the mythical successor Belo fought there at the battle of Bellina and concluded peace with the Hungarians.

The mentioned Ciaslavus some scholars identify with the Prince of Serbia, Časlav of Serbia (r. 933–943) from the 10th century De Administrando Imperio. The event some scholars date to c. 950 or 960, expanding Časlav rule and life. However, the account could be just a fantasy.