Battle of Halmyros.
The Battle of Halmyros was fought on 15 March 1311 between the Frankish Duchy of Athens and the Catalan Company (seal depicted). The Catalans were mercenaries hired by the Byzantine emperor to combat the increasing power of the Turks in Anatolia. After the Byzantines murdered the Catalan leader, Roger de Flor, the company crossed the southern Balkans and arrived in southern Greece in 1309. The new Duke of Athens, Walter of Brienne, hired them to attack Thessaly. The Catalans conquered much of the region, but Walter refused to pay them and prepared to forcibly expel them. The two armies met at Halmyros in southern Thessaly. The Catalans positioned themselves behind marshy terrain, but the Franks, confident in the prowess of their heavy cavalry, charged headlong against the Catalan line. The marsh impeded their attack, and the Frankish army was routed. Walter and almost all of his knights fell in the field, allowing the Catalans to take over the Duchy of Athens and rule it until the 1380s.
