E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Stow says, King Lud, repairing the city, called it after his name Luds town; the strong gate which he built in the west part he likewise named Lud-gate. In the year 1260 the gate was beautified with images of Lud and other kings. Those images, in the reign of Edward VI., had their heads smitten off . . Queen Mary did set new heads upon their old bodies again. The twenty-eighth of Queen Elizabeth the gate was newly and beautifully built, with images of Lud and others, as before. (Survey of London.) The more probable etymon of Lud-gate is the Anglo-Saxon leode (people), similar to the Porto del populi of Rome.
[Lud] Built that gate of which his name is hight,
By which he lies entombëd solemnly.
Spenser: Faërie Queene, ii. x. 46.
Ludgate was originally built by the barons, who entered London, destroyed the Jews houses, and erected this gate with their ruins. It was used as a free prison in 1373, but soon lost that privilege. A most romantic story is told of Sir Stephen Forster, who was lord mayor in 1454. He had been a prisoner at Ludgate, and begged at the gate, where he was soen by a rich widow, who bought his liberty, took him into her service, and afterwards married him. To commemorate this strange eventful history, Sir Stephen enlarged the prison accommodation, and added a chapel. The old gate was taken down and rebuilt in 1586. The new-built gate was destroyed in the Great Fire of London, and the next gate (used also as a prison for debtors) was pulled down in 1760, the prisoners having been removed to the London Workhouse, and afterwards to the Giltspur Street Compter.