The island was first inhabited in the Upper Palaeolithic (the Late Stone Age). The ancient Romans' Planasia had buildings including a theater and catacombs on two levels. It was extensively cultivated by the Romans. It became noted in history when the princeps Augustus banished his grandson and ex-heir Agrippa Postumus there in 6 or 7 CE. Postumus remained there until his execution around the death of Augustus in 14 CE.
In the Middle Ages the island's ownership was disputed by Pisa and Genoa. In 1399, it became part of Piombino. There were small colonies during fishing season in the following centuries, as well as several military strongholds.
Although 18th century documents report that it was once densely wooded, humans and the animals they brought have destroyed the trees on the island, which is now largely grassland