The building has been used as a town hall for several hundred years, and is still the ceremonial and administrative centre of the City of London and its Corporation.

It was the largest in Roman Britain, partial remains of which are on public display in the basement of the Guildhall Art Gallery, and the outline of whose arena is marked with a black circle on the paving of the courtyard in front of the hall.

[2] Excavations by Museum of London Archaeology at the entrance to Guildhall Yard exposed remains of the great 13th-century gatehouse built directly over the southern entrance to the Roman amphitheatre, which raises the possibility that enough of the Roman structure survived to influence the siting not only of the gatehouse and Guildhall itself but also of the church of St Lawrence Jewry whose strange alignment may shadow the elliptical form of the amphitheatre beneath.

The present grand entrance (the east wing of the south front), in "Hindoostani Gothic", was added in 1788 by George Dance.

[1] A more extensive restoration than that in 1670 was completed in 1866 by the City of London architect Sir Horace Jones, who added a new timber roof in close keeping with the original hammerbeam ceiling.

[12] Trials at the Guildhall have included those of Anne Askew (the Protestant martyr), Thomas Cranmer (Archbishop of Canterbury) and Lady Jane Grey ("the Nine Days' Queen")[13] as well as Henry Garnet (executed for his complicity in the Gunpowder Plot of 1605).

[14] The 1783 hearing of the infamous Zong case, the outcome of which focused public outrage about the transatlantic slave trade, also took place at Guildhall.

[17] Guildhall continues to serve as the headquarters for the City of London Corporation, with most of its offices housed in modern extensions to the north and west of the original building.

The North Wing was designed by Giles Gilbert Scott and was built between 1955 and 1958, facing a new public square between Aldermanbury and Basinghall Street.

They, in turn, were replaced by a new pair carved by David Evans in 1953 and given to the City of London by Alderman Sir George Wilkinson, who had been Lord Mayor in 1940 at the time of the destruction of the previous versions.