City on the Gulf of Salerno in southern Italy; originally a Greek colony. In the Dark Ages it belonged to the Duchy of Naples, a vassal-state of Byzantium, until it was conquered by the Lombard Principality of Benevento in 837. That principality split up almost immediately and Amalfi became independent in 839, a republic whose principal magistrate became known by the title of Duke in 958. The city came under Norman control in 1073, though there were ocasional efforts later to recover independence.
The Duchy had no territory outside the city. It was as a maritime and trading power that it found the wealth to be independent. Its influence long survived, not only its loss of independence, but also its facilities as a port, which were badly damaged by floods in 1343, because its maritime law, the Tavole Amalfitana, continued to serve the western Mediterranean until 1570.
The title of Duke of Amalfi was revived for the Piccolomini family, two of whose members married bastard descendants of the Aragonese Kings of Naples, 1458-1566. The eventual heiress did not suffer the terrible fate of the heroine of John Webster’s tragedy.