St Magnus-the-Martyr Great Plague of 1665, the City authorities ordered fires to be kept burning night and day, in the hope that the air would be cleansed. Daniel Defoe's semi-fictictional, but highly realistic, work "A Journal of the Plague Year" records that one of these was "just by St Magnus Church". Despite its escape in 1633, the church was one of the first buildings to be destroyed in the Great Fire of London in 1666. St Magnus stood less than 300 yards from the bakehouse of Thomas Farriner in Pudding Lane where the fire started. Farriner, a former churchwarden of St Magnus,
Ironmonger Lane was one of only two accesses to the Guildhall (the other being Lawrence Lane), a matter which made the travel of dignitaries difficult as two vehicles could not pass each other. The problem was alleviated after the fire when King Street was added by Christopher Wren to provide an additional access to Cheapside. Thomas Becket is said to have been born on the corner of Cheapside and Ironmonger Lane. The livery hall of the Worshipful Company of Mercers may lie on the same spot; it is a relatively modern building, the first hall having been destroyed in the Great Fire