One of the busiest spots in the City is Ludgate Circus, where meet Fleet Street, Ludgate Hill, Farringdon Street, and New Bridge Street. As may be seen from our view, the stately dome and towers of St. Paul's Cathedral are conspicuous objects from the Circus, although the railway bridge and the slender steeple of St. Martin's - one of Wren's churches - obstruct the view. The name Ludgate is derived from an old gate- the sixth and principal gate of London, says Stow in his " Survey" - which was taken down in 1760. Antiquaries, however, differ as to whether the gate was built by a King Lud, who flourished B.C. 66 (as Spenser has it in the "Faery Queen"), or whether the word is merely a corruption of Floodgate or Fleetgate.
source: The Queen's London : a Pictorial and Descriptive Record of the Streets, Buildings, Parks and Scenery of the Great Metropolis, 1896