Geoffrey was the elder son of Fulk V, King of Jerusalem and his wife Ermengarde of Maine. She was the daughter of Elias I of Maine. Geoffrey, born 24 August 1113, was named after his great-grandfather Geoffrey II, Count of Gâtinais. He received his nickname, Plantagenet, from the yellow sprig of broom blossom ("genêt" is the French name for the "planta genista", or broom shrub) he wore in his hat. King Henry I of England sent his royal to Anjou to arrange a marriage between Geoffrey and his daughter, Matilda. Consent was given by both parties. On 10 June 1128 King Henry I knighted the fifteen-year-old Geoffrey.