Thanks to numerous ancient written sources Baiae is considered the first and most famous Roman Thermal Spa and health resort which was frequented by rich aristocrats and emperors. There is even evidence for the existence of an imperial palatium thanks to various archaeological sources. Due to several developments, but mainly because of the volcanic activity of the Phlegraean Fields (bradyseism and the eruption of Monte Nuovo in 1538), Baiae disappeared from memory. It was only rediscovered during Renaissance in architectural remains found in a bay located about 17 km west of Naples in the so-called Phlegraean Fields.

Today, the bay is framed by the Epitaffio hill to the north and the mighty Castello Aragonese to the south. Thanks to the excavations carried out in the 20th century, extensive and complex Roman ruins can be presented to the public in a 4-hectare archaeological park in Baiae. There is also an underwater archaeological park, which not only provides vivid evidence of bradyseism, but also includes other ancient remains. Additionally, there are archaeological remains that extend across the bay. All the findings provide evidence of a Roman presence from the end of the Republican period until late antiquity. In view of the favourable starting position with numerous ancient texts, a large number of archaeological finds on land and under water, statues and inscriptions, it is all the more surprising that ancient Baiae has not yet been the focus of more research and has not been the subject of detailed studies.

The two lecturers addressed this desideratum and studied the architectural (M. Nieberle[1]) and decorative (L. Narès[2]) genesis of Baiae, whereby various further questions followed on from their respective doctoral theses. This presentation synthesises both research projects, with a focus on the Severan period. The two speakers are able to show that a detailed study of the decoration in conjunction with the architectural remains not only provides a better understanding of the topography of Baiae in Severan times, but even provides plausible evidence for the Severan palatium and its brief but impressive appearance. With the spectacular architecture and furnishing of monumental buildings, such as the so-called Temple of Diana, Baiae was a creative centre in terms not only of the thermal spa landscape, but also regarding monumental architecture and its decoration.