It is thought that Bishop John de Winchester (1435–60) was responsible for moving the main gate to the east wall which contained a strong portcullis. The architectural detail of the upper section of the gate remain and show the gatekeeper's room complete with small fireplace. John, as well as being the Bishop of Moray, was also the king's Master of Works and had been responsible for alterations to the castles at Inverness and Urquhart as well as the palace at Linlithgow. The fine stonework and styling of the gate may have been carried out by the master-masons working on the restoration work at Elgin Cathedral following its destruction in 1390.