Battle of Sellasia

Battle of Sellasia
Part of the Cleomenean War
A map of depicting the South Peloponnese.
Date 222 BC Location Sellasia, Laconia 37°10′N 22°25′E / 37.167°N 22.417°E / 37.167; 22.417 Result Decisive Macedonian-Achaean victory
Belligerents
League of Leagues Macedon Achaean League Boeotian League Acarnania Epirus	Sparta
Commanders and leaders
Antigonus III Doson Philopoemen Cercidas Alexander Demetrius of Pharos	Cleomenes III Eucleidas †
Strength
28,000 infantry, 1,200 cavalry	20,000 infantry, 650 cavalry
Casualties and losses
Substantial	Heavy 5,800 Spartans dead

The Battle of Sellasia took place during the summer of 222 BC between Macedon and the Achaean League, led by Antigonus III Doson, and Sparta under the command of King Cleomenes III. The battle was fought at Sellasia on the northern frontier of Laconia and ended in a Macedonian-Achaean victory.

In 229 BC, Cleomenes initiated hostilities against the Achaean League, the dominant power of the Peloponnese. In a series of campaigns, Cleomenes was successful in defeating the Achaeans, making Sparta the main regional power. This prompted the chief figure of the Achaean League, Aratus of Sicyon, to approach the King of Macedon, Antigonus III Doson, for military assistance. The Macedonians acquiesced on the terms that the Achaean surrender the formidable fortress of Acrocorinth to them. The Macedonians invaded the Peloponnese in 224 BC at the head of a Greek alliance and by 222 BC managed to hem Cleomenes in Laconia.

In the summer of 222 BC, the Macedonian and Achaean army advanced to Sellasia on the northern border of Laconia, where they encountered the awaiting army of Cleomenes. After a brief impasse, Antigonus launched an offensive against the Spartan positions on the fortified mountains of Olympus and Evas. While the Macedonian right flank routed the Spartan left wing on Evas, the battle on the other flank was heavily contested. After initially pushing back the Macedonian phalanx, the Spartans were driven from the field by the superior numbers of the Macedonians. Cleomenes was compelled to leave for exile in Alexandria and Antigonus became the first non-Spartan general to occupy Sparta.