Situated 11 kilometres north of Grosseto in the Ombrone Valley, Rusellae was one of the twelve city-states of the Etruscan Confederation. The city was an important ancient town of Etruria (roughly modern Tuscany) and subsequently of ancient Rome. It survived until the Middle Ages before being abandoned. The remains of the ancient buildings were brought to light by means of a long campaign of excavations carried out in the 1950s. More recent work has revealed many more impressive buildings.
The site was sparsely occupied during the Villanovan period, but the first urban centre dates to the 7th century BC when the first walled city was founded. About a century later, the town was provided with a new set of imposing defensive walls surrounding the hills on which it was located. In the Etruscan era, the town enjoyed a period of wealth and prosperity thanks not only to the exploitation of farming and mining resources but also to its commercial contacts with Greece and the Greek colonies of Southern Italy.
In the 4th century, the Romans built the via Aurelia and began intensifying their presence in the area. Initially, relations with the people of Rusellae were peaceful but eventually, the Romans and Etruscans came into conflict and battled against each other. This led to the Roman conquest of Rusellae in 294 BC. In 89 BC the inhabitants of the city became Roman citizens and members of the Scaptia tribe. The city experienced a long-lasting period of peace and prosperity with intense building activities, particularly during the eras between Claudius and Hadrian. Among the constructions were the paved square of the forum, the basilica, the office of the Augustales decorated with statues of the Julio-Claudian emperors, and the small amphitheatre set on the summit of the north hill.
Rusellae continued to thrive into the 4th century AD, but in the 5th century, it appeared half-abandoned. The Diocese of Roselle was established in AD 490. Between the end of the 6th century and the first half of the 7th century AD, the Lombards settled between the decumanus and the Roman workshops. In 1138 the diocese was suppressed and the site deserted. The episcopal seat was transferred to Grosseto.