The building was probably over 2½ stories high and was part of a forum — an open-air courtyard and marketplace, measuring about 328 feet by 164 feet, that was built on a raised platform at a high point of the city, Jackson said.
Archaeologists already knew where the ancient Roman basilica, the first of two to stand on the site, was located but did not know how much would remain after centuries of construction.
“We were really surprised by how much survived because the site’s been continuously occupied — certainly for 1,000 years,” Jackson said.
During the 1930s, when the current building on the site was built, an archaeologist came and was able to examine some of the Roman masonry — but it was only later in the century, after other discoveries, that experts realized the earlier basilica had stood on the site.
A team from MOLA was able to carry out initial archaeological investigations after developers gained planning permission to build a new office block in 2023.
The archaeologists dug trenches in the basement of the office building, which is still occupied and functioning, Jackson said. “And we were amazed that there’s actually a really, really substantial piece of the first Roman basilica surviving.”
After London and two other towns were destroyed during a revolt against Roman rule around A.D. 60, the creation of the first basilica, around A.D. 70-80, was “almost like a sign of renewal and commitment to London” by the Romans, Jackson noted.
The team found massive foundations and walls made of flint, ragstone and Roman tile. The discovery was, archaeologists believe, part of an area of the basilica known as the tribunal, where officials, magistrates and political leaders made important decisions affecting Roman London and perhaps even beyond.
About A.D. 100, work began to create a much larger forum around the site of the first — and about 20 years later, it was complete and the last traces of the original forum were demolished.
It’s unclear what prompted the Romans to build the second building so soon after the first, Jackson said — one of many questions archaeologists still have about the site.
Archaeologists hope to continue excavations and discover what the basilica looked like — how it was decorated, what materials were used and whether there were any inscriptions — as well as more about the origins of London, Jackson said.
The site’s developers have altered their planning request to allow for a permanent public display of the Roman remains.
Other ancient finds in London in recent years include a Roman-era mosaic floor thought to be at least 1,800 years old, which was uncovered at a construction site in the south of the city in 2022. And last year, archaeologists uncovered a section of a road built shortly after the Roman invasion of Britain.
