That the Roman city of Londinium boasted an amphitheatre was never subject of dispute. Its precise location, however, was unknown until comparatively recently. Excavations close to the old Roman road now known as Watling Street, during the construction of the Guildhall Art Gallery in 1988, revealed its stone foundations. Those are now preserved and open to the public, in situ where they were found, under the gallery.

The amphitheatre was built around AD 70, the same year that the Colosseum was begun in Rome. It was, understandably, considerably smaller, with seating for around 6,000 spectators as opposed to the Colosseum’s 75,000–although when you consider that 6,000 people represented about a quarter of the entire population of the city, it must have seemed a giant building indeed. Most of it was made of wood. Even in the following century, when it was improved and given stone entranceways, the tiers of seats would still have been of timber. The surviving remains are scanty: an illuminated backdrop showing scenes of raked seating and combatants in the arena gives a sense of the original dimensions of the building. In front of it is the surviving section of the eastern entrance to the arena, with side chambers that were perhaps guards’ houses or pens for wild animals. What is most remarkable are the preserved sections of timber drainage channel, complete with a silt sump to collect debris and prevent the drain from getting blocked. It operated by natural gravity, to flood the arena for mock sea battles, and to drain it again.

In common with most of the public structures of Roman Britain, the amphitheatre fell out of use in the 4th century, when the land fell prey to Scots, Picts and Saxons and when the emperors, harried by problems closer to home, stopped sending troops to defend this far-flung island. By the mid-fifth century, Londinium was an abandoned wasteland.