Testimonies from this period are from those who manned the watchtowers on the sea, which became the symbol of the island. With the Norman conquest of Southern Italy, Procida experienced feudal dominion; the island, with a mainland annex (the future Mount of Procida), came under the control of the Da Procida family which continued to hold the island for more than two centuries. The most famous member of the family was John III of Procida, counsellor to Emperor Frederick II and leader of the revolt of the Sicilian Vespers.