In 1480, forces of the Ottoman Empire under orders of Mehmed II captured Otranto, and massacred the majority of the inhabitants, but in the following year it was retaken by Ferdinand's son Alphonso, duke of Calabria. In 1482, abandoning his traditional position of paladin of the Papal States, he fought alongside Ferrara and Milan against the alliance of Sixtus IV and the Republic of Venice (see War of Ferrara).