Editing Demetrius I Poliorcetes (section)

===King of Macedonia===
[[File:Wall painting from Room H of the Villa of P. Fannius Synistor at Boscoreale MET DP140600.jpg|thumb|230x230px|A fresco in [[Pompeii]] possibly depicting [[Lanassa (wife of Pyrrhus)|Lanassa]] and Demetrius I, ca. 50–40 BC.{{citation needed|date=February 2022}}]]
In 294 BC, he established himself on the throne of Macedonia by murdering [[Alexander V of Macedon|Alexander V]], the son of Cassander.<ref name="EB1911" /> He faced rebellion from the [[Boeotians]] but secured the region after [[Siege of Thebes (292-291 BC)|capturing Thebes]] in 291 BC. That year he married [[Lanassa (wife of Pyrrhus)|Lanassa]], the former wife of [[Pyrrhus of Epirus|Pyrrhus]], but his new position as ruler of Macedonia was continually threatened by Pyrrhus, who took advantage of his occasional absence to ravage the defenceless part of his kingdom ([[Plutarch]], ''Pyrrhus'', 7 ff.); at length, the combined forces of Pyrrhus, Ptolemy and Lysimachus, assisted by the disaffected among his own subjects, obliged him to leave Macedonia in 288 BC.<ref name="EB1911" />

After [[Siege of Athens (287 BC)|besieging Athens]] without success he passed into Asia and attacked some of the provinces of Lysimachus with varying success. Famine and pestilence destroyed the greater part of his army, and he solicited Seleucus' support and assistance. However, before he reached Syria hostilities broke out, and after he had gained some advantages over his son-in-law, Demetrius was totally forsaken by his troops on the field of battle and surrendered to Seleucus.

His son [[Antigonus II Gonatas|Antigonus]] offered all his possessions, and even his own person, in order to procure his father's liberty, but all proved unavailing, and Demetrius died after a confinement of three years (283 BC). His remains were given to Antigonus and honoured with a splendid funeral at [[Corinth, Greece|Corinth]]. His descendants remained in possession of the Macedonian throne until the time of [[Perseus of Macedon|Perseus]], when Macedon was conquered by the [[Roman Republic|Romans]] in 168 BC.<ref name="EB1911"/>