Pausanias Description of Greece 1.10.2

[2] For these reasons he clashed with Demetrios at Amphipolis and came near to being pushed out from Thrace, 41

but after Pyrrhos came 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 Pyrrhos himself, who came from Epeiros with an army and was at that time on friendly terms with Lysimakhos. When, however, Demetrios crossed over into Asia (Minor) and made war on Seleukos, the alliance between Pyrrhos and Lysimakhos lasted only as long as Demetrios continued hostilities; when Demetrios submitted to Seleukos, the friendship between Lysimakhos and Pyrrhos was broken, and when war broke out Lysimakhos fought against Antigonos son of Demetrios and against Pyrrhos himself, had much the better of the struggle, conquered Macedonia and forced Pyrrhos to retreat to Epeiros.