During the High Middle Ages the city grew into a very important commercial and naval center and controlled a significant Mediterranean merchant fleet and navy. It expanded its influence through the sack of Reggio di Calabria in the south of Italy in 1005. Pisa was in continuous conflict with the Saracens for control of the Mediterranean. In alliance with Genoa, Sardinia was captured in 1016 with the defeat of the Saracen leader Mujāhid al-‘Āmirī (). This victory gave Pisa supremacy in the Tyrrhenian Sea. When the Pisans subsequently ousted the Genoese from Sardinia, a new conflict and rivalry was born between the two maritime republics. Between 1030 and 1035 Pisa went on to successfully defeat several rival towns in the Emirate of Sicily and conquer Carthage in North Africa. In 1051–1052, Admiral Jacopo Ciurini conquered Corsica, provoking more resentment from the Genoese. In 1063, the Pisans approached the Norman Roger I of Sicily, who was conducting a campaign to conquer Sicily that would last over three decades, with the prospect of a joint attack against Palermo. Roger declined due to other commitments. With no land support, the Pisan attack against Palermo failed.