Mehmed II started preparations to respond to the destruction caused by the Venetian navy on the islands and
Enez, and to capture this island, which was considered an outpost of the
Venetians. However, these preparations were kept secret and the expedition was presented as if it would be on
Rhodes. Finally, a large fleet under the command of Mahmud Pasha set out from
Gallipoli in 1470, captured the island of Shira on the way, and then besieged Negroponte. The Venetians sent a relief force under the command of
Nicolò Canal, known as "a man of letters rather than a fighter, a learned man readier to read books than direct the affairs of the sea." The relief force could not prevent the Turkish fleet from entering the Negroponte canal on June 14, 1470. Simultaneously, Mehmed II arrived before Negroponte by land with a force of 70 thousand soldiers. He gathered his ships on the part of the island closest to the land and built a bridge connecting the land and the island for three days. In this way, cannons could be transported to the island by horses. Now the
castle was surrounded by both sea and land, with one side of the sea route remaining open in front of the castle, where the defenders could more easily target enemy ships. For this reason, as was done for
the fall of Constantinople, some of the ships were transported by land to the other side of the castle and thus that road was also closed. The first attack on the castle started from the shore. The castle was well defend, including by very high walls built of chipped
stones from the ground up and reinforced with lime and mortar. There was also a deep
ditch dug on the beach side. The Ottomans placed numerous
mortars,
cannons,
rifles and springs around the castle and bombarded. Despite efforts from the defenders to repair the walls, some were soon sufficiently damaged to allow an attack. The
Venetian fleet attempted to come to the aid of the defenders, including by destroying the bridge between the island where the castle stood and the land, to little effect. The Venetian navy then entered the harbor and attempted to land soldiers to come to the aid of the garrison. A naval battle ensued, ending in Turkish victory, with the loss of several ships by the Venetians and the deaths of several of their captains, including
Captain Zuan Longo and Zuan Tran. The Venetian commander, admiral Nicolò Canal, was severely criticized for his role in this defeat, leading to his dismissal and exile. The siege continued for several days following the defeat of the Venetian relief force. The Turkish launched their final attack against the castle started on the night of Wednesday, July 11, 1470, and continued until the morning, and the castle fell on Thursday, July 12. ==Aftermath==