ridaeus reigned, and after him Cassander and his sons, friendly relations continued between Lysimachus and Macedon. But when the kingdom devolved upon Demetrius, son of Antigonus, Lysimachus, henceforth expecting that war would be declared upon him by Demetrius, resolved to take aggressive action. He was aware that Demetrius inherited a tendency to aggrandise, and he also knew that he visited Macedonia at the summons of Alexander and Cassander, and on his arrival murdered Alexander himself294 B.C. and ruled the Macedonians in his stead.
Therefore encountering Demetrius at Amphipolis he came near to being expelled from Thrace288 B.C., but on Pyrrhus' coming to his aid he mastered Thrace and afterwards extended his empire at the expense of the Nestians and Macedonians. The greater part of Macedonia was under the control of Pyrrhus himself, who came from Epeirus with an army and was at that time on friendly terms with Lysimachus. When however Demetrius crossed over into Asia and made w