Guild certificates of 1388/89 (12 Richard II) record that the Confraternity of Salve Regina and the guild of St Thomas the Martyr in the chapel on the bridge, whose members belonged to St Magnus parish, had determined to become one, to have the anthem of St Thomas after the Salve Regina and to devote their united resources to restoring and enlarging the church of St Magnus. An Act of Parliament of 1437 provided that all incorporated fraternities and companies should register their charters and have their ordinances approved by the civic authorities. Fear of enquiry into their privileges may have led established fraternities to seek a firm foundation for their rights. The letters patent of the fraternity of St Mary and St Thomas the Martyr of Salve Regina in St Magnus dated 26 May 1448 mention that the fraternity had petitioned for a charter on the grounds that the society was not duly founded. In the mid-14th century the Pope was the Patron of the living and appointed five rectors to the benefice. Henry Yevele, the master mason whose work included the rebuilding of Westminster Hall, the naves of Westminster Abbey and Canterbury Cathedral and the tomb of John of Gaunt and his first wife Blanche of Lancaster in old St Paul’s, was a parishioner and rebuilt the chapel on London Bridge between 1384 and 1397. He served as a warden of London Bridge and was buried at St Magnus on his death in 1400. His monument was extant in John Stow's time, but was probably destroyed by the fire of 1666. Yevele, as the King’s Mason, was overseen by Geoffrey Chaucer in his capacity as the Clerk of the King's Works. In The General Prologue of Chaucer's The Canterbury Tales the five guildsmen "were clothed alle in o lyveree Of a solempne and a greet fraternitee" and may be thought of as belonging to the guild in the parish of St Magnus, or one like it. Chaucer's family home was near to the bridge in Thames Street. St Magnus appears several times in Anya Seton's historical novel Katherine, which is set in the 14th century. 15th and 16th centuries: before and after the Reformation In 1417 a dispute arose concerning who should take the place of honour amongst the rectors in the City churches at the Whit Monday procession, a place that had been claimed from time to time