The Synod of Westminster in 1102 is recorded as taking measures to restore Bangor Cathedral, but the earliest part of the present building was built during the episcopate of Bishop David (1120–1139) with the assistance of the king of Gwynedd, Gruffudd ap Cynan, who donated money towards the project and was buried by the high altar on his death in 1137. This was a cruciform building in the Norman style, about 44 yards in length. Gruffudd's son, Owain Gwynedd, was also buried here, as was his brother Cadwaladr. Giraldus Cambrensis describes a service held here in 1188 when the Archbishop of Canterbury celebrated Mass.