Soon after the peace was reached with Bulgaria, the internal strife hit the ruling triumvirate. Mutimir, eldest and probably the most powerful in the state, expelled his brothers Strojimir (and his son Klonimir) and Gojnik to khan Boris in Bulgaria, keeping only Petar Gojniković, Gojnik's son and his nephew. This happened between 863 and 873, when the pope John VIII in his letter addressed Mutimir only. However, Petar soon fled to Croatia. Strojimir remained in Bulgarian exile for the rest of his life. Boris married him to a Bulgarian noblewoman and they had a son, Časlav Klonimirović.