According to Fine, his brief reign mostly included family quarrels with his mother and siblings. In 1457, Lazar gave an oath of subservience to Mehmed II, son and successor of Murad II. Fine considers this to be an attempt to prevent an Ottoman invasion. His only other decision of consequence was to appoint Mihailo Anđelović, a member of the Angelos family, as his chief official. Mihailo would briefly serve as head of a regency council following the death of his lord.