Ptolemy of Aloros in Wikipedia

Ptolemy of Aloros (Greek: Πτολεμαῖος), was sent by King Amyntas as an envoy to Athens c. 375-373 BC. After Amyntas' death, he began a liaison with his widow, Eurydice. In 368, he assassinated her son, his predecessor Alexander II in order to gain control of the throne. This caused a stir in the families of Macedon, which called in Pelopidas to reestablish peace. As part of the peace settlement, Philip, Alexander II's brother, was taken as hostage to Thebes. Ptolemy ruled as a regent for Perdiccas III until Perdiccas killed him in 365 BC. It is suggested that Ptolemy was descended from Amyntas brother of Menelaus, son of Alexander I.