Regent of Macedonia
When Demetrius II died in battle in 229 BC, his son and would-be successor, the later Philip V, was only nine years old. According to Plutarch, both the Macedonian army and nobility thought the political situation too volatile to wait for Philip V to mature enough to assume command. As a consequence, the Macedonian nobility turned to Doson, who was subsequently made regent of the kingdom and married to his predecessor's widow and the mother of Philip, Chryseis. However, it was only after Doson demonstrated his leadership abilities by succeeding (where his cousin Demetrius had failed) in defeating the Dardanii invaders and also in putting down a rebellion by the Thessalians, and showing his rule to be generally moderate and good, that he given the title of king. Unlike his Antigonid ancestors, he had no viable rivals to challenge his right to rule. Yet, even as king he apparently envisioned himself as caretaker for his cousin's son, Philip V.
Read more about this topic: Antigonus III Doson