Ottoman invasion of Otranto
1481 CE.
Shown on the map at 40.150°, 18.483°.
In the summer of 1480, the Ottoman Empire invaded southern Italy, and laid siege to Otranto (Kingdom of Naples), finally capturing it on 11 August. This was their first outpost in Italy. According to a traditional account, more than 800 inhabitants were beheaded after the city had been captured, because they would not renounce their Christian faith. The Martyrs of Otranto are still celebrated in Italy. A year later, Otranto was surrendered by the Ottomans to Duke Alfonso of Calabria after a siege by Neapolitan troops, supported by a Papal fleet (under Paolo Fregoso of Genoa) and Hungarian forces, and amid uncertainty upon the death of sultan Mehmed II.
Text from the Wikipedia article Ottoman conquest of Otranto, licensed CC BY-SA 4.0.