Battle of Pelagonia

Part of the Byzantine-Latin Wars and Epirote–Nicaean conflict

Date	September 1259
Location	Pelagonia
Result	Decisive Nicaean victory

Belligerents

Principality of Achaea
Despotate of Epirus
Kingdom of Sicily

Empire of Nicaea

Commanders and leaders

William II of Achaea (POW)
Michael II of Epirus
John of Thessaly (defected)

John Palaiologos
Alexios Strategopoulos
John of Thessaly

Strength

Unknown, but more than the Nicaeans

6,000 men

Casualties and losses

Heavy

Unknown

The Battle of Pelagonia took place in September 1259, between the Empire of Nicaea and the Despotate of Epirus, Sicily and the Principality of Achaea. It was a decisive event in the history of the Eastern Mediterranean, ensuring the Byzantine reconquest of Constantinople and the end of the Latin Empire in 1261, and marks the beginning of the Byzantine recovery of Greece. This battle is also notable for being the last appearance of the famous Varangian Guard.

The exact location of the battle remains unclear. It has been called the Battle of Kastoria, after the region in western Greek Macedonia, because three Byzantine sources (i.e. Pachymeres, George Akropolites and Nikephoros Gregoras) inform us that the Epirote camp was first attacked there in a location called Boril's Wood (Βορίλλα λόγγος). However, since the conflict also includes a siege of Prilep, it is justifiably called the Battle of Pelagonia.

The Nicaean emperor, Theodore II Laskaris, died in 1258 and was succeeded by the young John IV Laskaris, under the regency of Michael VIII Palaiologos, who was determined to restore the Byzantine Empire and recapture all of the territory it held before the Fourth Crusade. In 1259, William II Villehardouin married Anna Komnene Doukaina (also known as Agnes), daughter of Michael II of Epirus, cementing an alliance between the Despotate of Epirus and Achaea against Nicaea. They also allied with Manfred of Sicily who sent them 400 knights.

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Wikipedia