The name Sulis continued to be used after the Roman invasion, leading to the town's Roman name of Aquae Sulis ("the waters of Sulis"). The temple was constructed in 60-70 AD and the bathing complex was gradually built up over the next 300 years. During the Roman occupation of Britain, and possibly on the instructions of Emperor Claudius, engineers drove oak piles to provide a stable foundation into the mud and surrounded the spring with an irregular stone chamber lined with lead. In the 2nd century it was enclosed within a wooden barrel-vaulted building, and included the caldarium (hot bath), tepidarium (warm bath), and frigidarium (cold bath). After the Roman withdrawal from Britain in the first decade of the 5th century, these fell into disrepair and were eventually lost due to silting up and flooding. The Anglo-Saxon Chronicle suggests the original Roman baths were destroyed in the 6th century.
About 130 curse tablets have been found. Many of the curses related to thefts of clothes whilst the victim was bathing. This collection is the most important found in Britain.