Battle of Halmyros

Date: March 15, 1311 • Location: Almyrós, Greece

This milestone marked the outbreak and beginning of this historic period, which spanned 1311.

In the Battle of Halmyros, the Catalan Company defeated the forces of Walter V, Count of Brienne, taking control of the Duchy of Athens, a Crusader state in present-day Greece.

The Battle of Halmyros, known by earlier scholars as the Battle of the Cephissus or Battle of Orchomenos, was fought on 15 March 1311, between the forces of the Frankish Duchy of Athens and its vassals under Walter of Brienne against the mercenaries of the Catalan Company, resulting in a decisive victory for the mercenaries.