Duchy of Gaeta

The Duchy of Gaeta was an early medieval state centered on the coastal south Italian city of Gaeta, existing from 839 to 1140. It emerged in the early ninth century as the local community gained growing autonomy while Byzantine authority weakened across the Mediterranean and the Italian peninsula under pressure from Lombard and Saracen incursions. Constantine of Gaeta served as its first duke from 839 to 866, and the duchy was governed under an oligarchic system; its history is unusually well documented for the period through the surviving Codex Caietanus, which records it in more detail than neighboring Tyrrhenian duchies such as Naples, Amalfi and Sorrento. The duchy passed from Byzantine allegiance to Norman overlordship and ended in 1140, when its last duke, Richard III of Gaeta, who had submitted to Roger II of Sicily in 1135, died and Roger II absorbed the territory into the Kingdom of Sicily.