Lazaretto Island (formerly known as Aghios Dimitrios) is located two nautical miles north-east of Corfu (). In the early 16th century, when Corfu was under Venetian rule, a monastery was established on the islet for prevention of diseases. Later that century, the island was renamed Lazaretto, after the leprosarium that was set up there. In 1798, when the French ruled Corfu, the Russo-Turkish fleet took over the islet and ran it as a military hospital. In 1814, during the British occupation, the leprosarium was renovated and went into operation again. After the Ionian Islands were united with Greece (1864), the leprosarium only operated when needed.