During the 15th century, the church’s incumbents included two Italian courtiers and diplomats. Between 1477 and 1482, Giovanni Gigli was priest in charge and after him, Peter Carmelianus was priest in charge for 37 years. Earlier still, the church had connections with Royalty. Richard II pardoned a murderer at the church in August 1392 and Henry V met the Aldermen of the City at the steps of the church on his return to London after his French campaigns during the Hundred Years War in the early 15th century, his most significant victory being at Agincourt in 1415.
During the medieval period, there was a guild in the church dedicated to St. George and the Virgin Mary. The earliest mention of the guild is in the period 1459-65, and gained royal license for its representatives to collect arms nationally. Annually, 1,044 masses were said of sung in the church by the three guild priests for its deceased members souls in the early 16th century. Henry VII’s queen, Elizabeth of York, contributed 5 shillings to the guild in 1502 and her son, Henry VIII, made a contribution of 13 shillings 4 pence to the guild on St. George’s Day 1529. The guild would have had lay members who would contribute to the upkeep of perhaps statues of St George and the Virgin Mary and maintain candles in front of them. Funds would also be collected to help guild members in times of need and perhaps they had their own unique livery. However, the effect of the Reformation was felt at St. George’s, and with the suppression of guilds and chantry masses, by 1541, the guild only maintained one priest. By 1548, the guild ceased to exist as a vibrant expression of popular piety in the parish.