He fought in the campaigns of 1291/92 against the Byzantine Greeks of the Despotate of Epirus, and inherited rule over one half of Thebes from his uncle Otho of Saint-Omer at his death, sometime before 1299.
He participated in the military campaigns against Byzantine Greeks in the Despotate of Epirus in 1291/92 and inherited control over one-half of Thebes from his uncle Otho of Saint-Omer before 1299, shortly after his uncle's passing.