The Hall of St Michael and St George, also known as the Throne Room, of the Grandmaster's Palace, Valletta, is decorated with 13 of his frescoes showing the events of the great siege of Malta by the Turks in 1565. He is credited with having introduced mannerism to Malta with his frescoes. These were painted from 1575 to 1581, at the same time as the oil paintings of the same scene, four of which can be found in the Cube Room of the Queen's House, Greenwich, London. Among his other works in Malta there is the Baptism of Christ which was originally the titular painting of the St. John's Co-Cathedral.