The aisle was built in about 1300 in the Decorated style, and is thought to have fallen into ruin before the Dissolution of the priory in 1539 due to structural failure caused by poor foundations.
The identity of St Bees Man is now considered almost certainly to be Anthony de Lucy, who may have been born in 1332/1333 and was probably killed in 1368, fighting for the Teutonic Knights in the Northern Crusades against the Lithuanians.
[3][4] This was established in 2010 after an osteobiographical approach was taken in identifying the skeleton of the woman who was buried with him, which was still available for analysis using modern methods developed since the remains were found in 1981.
Warwick had been on crusade to Lithuania previously and probably saw a way to re-direct the troublesome energies of de Lucy away from the Scottish Marches.
Maud also inherited considerable estates after the death of her first husband Gilbert de Umfraville in 1380/81, and probably in a move to ally herself politically with the Percy family, Henry Percy purchased the licence fee on Gilbert's lands and, therefore, the hand of Maud in 1381.
Maud's connection with St Bees is proven by an existing stone in the priory belfry which carries the quartered arms of the de Lucy and Percy families.
Maud insisted on this quartering as part of the marriage agreement, probably so that the de Lucy arms should be perpetuated.