Geoffrey II of Brittany was a medieval nobleman born around 1158. He was the son of Henry II of England and Eleanor of Aquitaine, making him a member of the powerful Plantagenet dynasty. Geoffrey became the Duke of Brittany in 1186 after his marriage to Constance of Brittany, which helped strengthen ties between England and Brittany. Geoffrey was known for his political maneuvering and efforts to maintain the autonomy of Brittany. He had several children, including Arthur of Brittany, who later became a significant figure in the conflict between the Plantagenets and the French crown. Geoffrey died in 1186, leaving a legacy intertwined with the history of both England and Brittany.