Geoffrey was the eldest son of Fulk II, Count of Anjou and his first wife Gerberga. He succeeded his father as Count of Anjou about 960,at the age of 20. He married Adele of Meaux, daughter of Robert of Vermandois and Adelais de Vergy. On her mother's side she was a granddaughter of king Robert I of France and on her father's side a direct descendant of Charlemagne. Through this marriage the Angevins joined the highest ranks of western French nobility.
Geoffrey started by making his power-base the citadel of Angers strategically placing his fideles in key areas surrounding the city to protect his territories. The lands of the abbeys of Saint-Aubin and Saint-Serge in Angers provided the beneficium for his most faithful adherents. On this subject which became this family's theme, Geoffrey advised both his sons, Fulk and Maurice: "No house is weak that has many friends. Therefore I admonish you to hold dear those fideles who have been friends." Although one of the principal methods of Angevin expansion was by the creation of family connections Geoffrey exerted his control through various methods. His father had controlled Nantes through his second marriage to the widowed countess and Geoffrey continued this by making Count Guerech accept him as overlord. With an eye towards Maine, Geoffrey took advantage of the rift that developed between the Counts of Maine and the viscounts and Bishops of Le Mans. About 971 Geoffrey secured the see of Le Mans for his ally Bishop Seinfroy. In 973 Geoffrey had married his daughter Ermengarde-Gerberga to Conan I of Rennes but Conan began to oppose Geoffrey and in 982 the two met at the first battle of Conquereuil with Geoffrey defeating Conan.
Geoffrey had influence in Aquitaine by way of his sister Adelaide-Blanche's first marriage to the powerful baron Stephen, Count of Gevaudan and Forez who after his death the lands were ruled by Adelaide. His nephews Pons and Bertrand succeeded as counts there and his niece Adalmode married Adelbert, Count of Marche and Périgord. In 975 Geoffrey had his brother Guy appointed Count and Bishop of Le Puy. In 982 Geoffrey married his now widowed sister Adelaide-Blanche to the fifteen-year-old Louis V of France, the two being crowned King and Queen of Aquitaine. But the marriage to a woman thirty years his senior failed as did Geoffrey's plans to control Aquitaine through his young son-in-law. After the death of his first wife Adele, Geoffrey married secondly Adelaise de Châlon and for nearly a decade exerted control over the county of Châlons. Through the marriage of his son, Fulk III, to Elisabeth the heiress of Vendôme Geoffrey brought that county into the Angevin sphere of influence. Fortunately it was at this same time Geoffrey made his son Fulk Nerra his co-ruler since he died shortly thereafter while besieging the fortress of Marcon on 21 July 987 (wikipedia)