a port at the Danube. This building endeavor was one of the most elaborate military architecture achievements of the Middle Ages. After the siege, the Hungarians reinforced the north and eastern side with an additional gate and several towers, one of which, the Nebojša Tower, was designed for artillery purposes. On July 14, 1456, Hunyadi arrived to the completely encircled city with his flotilla on the Danube, while the Ottoman navy lay astride the Danube River. He broke the naval blockade on July 14, sinking three large Ottoman galleys and capturing four large vessels and 20 smaller ones. By destroying the Sultan's fleet, Hunyadi was able to transport his troops and much-needed food into the city. The fort's defense was also reinforced. But Mehmed II was not willing to end the siege and after a week of heavy bombardment, the walls of the fortress were breached in several places. On July 21 Mehmed ordered an all-out assault that began at sundown and continued all night. The besieging army flooded the city and then started its assault on the fort. As this was the most crucial moment of the siege, Hunyadi ordered the defenders to throw tarred wood and other flammable material, and then set it afire. Soon a wall of flames separated the Janissaries fighting in the city from their fellow soldiers trying to breach through the gaps into the upper town. The fierce battle between the encircled Janissaries and Szilágyi's soldiers inside the upper town was turning in favour of the Christians, and the Hungarians managed to beat off the fierce assault from outside the walls. The Janissaries remaining inside the city were thus massacred while the Ottoman troops trying to breach the upper town suffered heavy losses. Battle The next day something unexpected happened. By some accounts, the peasant crusaders started a spontaneous action, and forced Capistrano and Hunyadi to make use of the situation. Despite Hunyadi's orders to the defenders not to try to loot the Ottoman positions, some of the units crept out from demolished ramparts, took up positions across from the Ottoman line, and began harassing enemy soldiers. Ottoman Sipahis tried without success to disperse the harassing force. At once, more defenders joined those outside the wall. What began as an isolated incident quickly escalated into a full-scale battle. John of Capistrano at first tried to order his men back inside the walls, but soon