The northern edge of Tudor London (1520)
Moorgate was an old gate in London's city wall, situated to the west of where the River Walbrook - a long lost river of London - crossed into the city. The Walbrook ran between the two main hills of the city: Ludgate Hill to the west and Cornhill to the east. It rose in the Shoreditch area and flowed into the Thames.
By Tudor times, the Walbrook had been culverted within the city but still ran in open country outside the wall. After the river crossed London Wall and flowed into the City, it was bricked over since it had long since turned into a sewer there.
Outside the London Wall, the open Walbrook would regularly flood the low-lying area to the north making building difficult. William Fitzstephen described the 'great fen which washed against the northern wall of the City'. So whereas London slowly spread to the west and the east, the marshy conditions of Moorfields hindered urbanisation to the north. The marsh covered much of the Manor of Finsbury - the name of the district immediately to the north of the city of London whose placename 'Finsbury' derives from the word 'fen'.
London's Wall seems to have acted as a dam, restricting the flow of the river and adding to the area of marshland.
As the Walbrook north of the wall was culverted in time, this slowly opened up the hitherto marshy land for building.
None of Moorfields remains now - lending its name to the eye hospital and little else.
Attribution: Historic Towns Trust/Col. Henry Johns
