St Paul's Cathedral stood at the centre of religious life in medieval London. It was the mother church of the diocese, a principal landowner in the capital and surrounding countryside, and a theatre for the enactment of events of national importance. The cathedral was also a powerhouse of commemoration and intercession, where prayers and requiem masses were offered on a massive scale for the salvation of the living and the dead. This spiritual role of St Paul's Cathedral was carried out essentially by the numerous chantry priests working and living in its precinct. Chantries were pious...