Fulk, born 1043, was the younger son of Geoffrey II, Count of Gâtinais and Ermengarde-Blanche of Anjou. Ermengarde-Blanche was a daughter of Fulk Nerra, count of Anjou, When Geoffrey Martel died without direct heirs he left Anjou to his nephew Geoffrey III, Fulk le Réchin's older brother. Geoffrey III was not an effective count. In 1062 Geoffrey failed to defend Saintonge and it was lost. In 1063 the county of Maine was lost to Anjou. In 1065 Geoffrey angered Archbishop Barthelemy of Tours and was excommunicated.