Answer
301 BC marked the end of Antigonus I Monophthalmus' reign, the powerful Macedonian general and founder of the Antigonid dynasty. Having carved out an extensive empire following the collapse of Alexander the Great's realm, Antigonus I's ambitions met their match at the decisive Battle of Ipsus. There, a coalition of rival Hellenistic rulers decisively defeated his forces, resulting in his demise and reshaping the political landscape of the ancient world.