Building on the great Norman church began in 1090, and the whole monastery was substantially completed by the end of the 13th century. Having to maintain a priory, providing suitable accommodation and hospitality for many Royal parties, was always a costly business but at Tynemouth the priors were also responsible for the upkeep of the castle and the garrison. The wealth they accumulated from their coal industries was much needed. Perhaps the most notable feature of the buildings at Tynemouth Priory is the thickness of its walls, presumably because of its location and the fact that it was used as much as a fortress as a priory.