Gerard was Archbishop of York between 1100 and 1108 and Lord Chancellor of England from 1085 until 1092. A Norman, he was a member of the cathedral clergy at Rouen before becoming a royal clerk under King William I of England and subsequently his son King William II Rufus. Gerard was appointed Lord Chancellor by William I, and he continued in that office under Rufus, who rewarded him with the Bishopric of Hereford in 1096. Gerard may have been with the king's hunting party when William II was killed, as he is known to have witnessed the first charter issued by the new king, Henry I of England, within days of William's death.

The archbishop of York is a senior bishop in the Church of England, second only to the archbishop of Canterbury. The archbishop is the diocesan bishop of the Diocese of York and the metropolitan bishop of the province of York, which covers the northern regions of England as well as the Isle of Man.