Domes were a characteristic element of the architecture of Ancient Rome and of its medieval continuation, the Byzantine Empire. They had widespread influence on contemporary and later styles, from Russian and Ottoman architecture to the Italian Renaissance and modern revivals. The domes were customarily hemispherical, although octagonal and segmented shapes are also known, and they developed in form, use, and structure over the centuries. Early examples rested directly on the rotunda walls of round rooms and featured a central oculus for ventilation and light. Pendentives became common in the Byzantine period, provided support for domes over square spaces.

Baiae was an ancient Roman town situated on the northwest shore of the Gulf of Naples and now in the comune of Bacoli. It was a fashionable resort for centuries in antiquity, particularly towards the end of the Roman Republic, when it was reckoned as superior to Capri, Pompeii, and Herculaneum by wealthy Romans, who built villas here from 100 BC. Ancient authors attest that many emperors built in Baia, almost in competition with their predecessors and they and their courts often stayed there. It was notorious for its hedonistic offerings and the attendant rumours of corruption and scandal.