A Crusader force of between 500 and 700 knights and infantry under the command of William of Champlitte and Geoffrey I of Villehardouin advanced into the Morea to deal with Byzantine resistance. In the olive grove of Kountouras in Messenia, they confronted an army of around 4,000–5,000 local Greeks and Slavs under the command of a certain Michael, sometimes identified with Michael I Komnenos Doukas, the founder of the Despotate of Epirus. In the ensuing battle, the Crusaders emerged victorious, forcing the Byzantines to retreat and crushing resistance in the Morea. This battle paved the way for the foundation of the Principality of Achaea.