It is not without some irony that bombards, all but abandoned as obsolete by most European powers by 1453, played a critical role that year in the fall of Constantinople, the last Christian stronghold in the East. For centuries the Byzantine capital’s great walls and defenders had repulsed invaders, including an earlier 1422 attempt by Sultan Murad II (r. 1421–1451). Although Murad had employed bombards against the city, they were rather ineffective, and he subsequently withdrew. His successor, however, Mohammad II, sometimes known as Mehmed II (b. 1432; r. 1444–1446, 1451– 1481), and also known as Muhammad the Conqueror, possessed an innate appreciation for artillery and its use in siege craft.

Muhammad, lacking technical experts among his own subjects, subsequently obtained the services of Christian gun founders to design and build cannons especially suited for the siege. Among these was reportedly a famed Hungarian cannon maker known as Urban. Urban (or Orban) had previously been hired by the Byzantines but had deserted their cause after they failed to meet his fees. Muhammad, unlike the Byzantines, appreciated Urban’s considerable, although mercenary, talents and “welcomed him with open arms, treated him honorably and provided him with food and clothing; and then he gave him an allowance so generous, that a quarter of the sum would have sufficed to keep him in Constantinople” (De Vries, X 356).

Urban quickly established a gun foundry at Adrianople where he oversaw the casting of both a number of large iron and bronze guns. These included at least one huge bombard of cast iron reinforced with iron hoops and with a removable, screw-on breech. Typical of such large breechloading cannons, the gun was fitted with slots around the breech’s circumference to accept stout wooden beams. For loading and unloading, these beams were inserted in the slots to act as a capstan and provide the leverage to unscrew the heavy powder chamber. Weighing more than 19 tons, the gun was capable of firing stone balls weighing from approximately 800 to 875 pounds. The sheer size of the bombard, known as Basilica, required forty-two days and a team of sixty oxen and a thousand men to traverse the 120 miles to its firing site at Constantinople.

Muhammad began preparations for the siege in February and ordered the positioning of fourteen artillery batteries around the city. As a further preparation, he ordered his navy, also equipped with artillery, to cut Constantinople off from the sea. For his part, the Byzantine emperor, Constantine XI (b. 1409; r. 1449–1453), did possess some artillery, but it was for the most part obsolete and numerically insufficient to reply to Muhammad’s forces. The Byzantines had long lost the technological superiority they had held in previous centuries, and they soon found themselves reckoning with their shortsightedness in snubbing Urban the Hungarian.

Muhammad began the bombardment of the city on 6 April 1453. With a keen eye for the city’s weaknesses, he concentrated his guns against its most vulnerable points, including the Gate of St. Romanus, where they affected a breach on 11 April. His success was short lived, however, as the defenders counterattacked and repaired the damage. Muhammad also faced other setbacks when Urban was killed when a cannon he was supervising exploded, and when his giant bombard cracked after a few days of firing, necessitating repairs. The sultan, however, proved his own resourcefulness in the use of artillery and made much better use of his smaller guns—weapons that were capable of a much higher rate of fire than Basilica’s three rounds a day and were also more maneuverable. These included eleven bombards capable of firing 500-pound shot and fifty guns firing 200-pound balls.

The Ottoman barrage continued day and night, wearing down both the city’s walls and its defenders. A witness described its effect:

And the stone, borne with tremendous force and velocity, hit the wall, which it immediately shook and knocked down, and was itself broken into many fragments and scattered, hurling the pieces everywhere and killing those who happened to be nearby. Sometimes it demolished a whole section, and sometimes a half-section, and sometimes a larger or smaller section of tower or turret or battlement. And there was no part of the wall strong enough or resistant enough or thick enough to be able to withstand it, or to wholly resist such force and such a blow of the stone cannon-ball. (ibid., X 357–358)

Finally, on 29 May 1453, the walls on either side of the St. Romanus Gate collapsed, and the Turks stormed the city. The Emperor Constantine fought valiantly in the defense of his city, but he was killed as overwhelming numbers of Turkish troops rampaged through the city for three days, killing, looting, and raping. With the fall of its capital, the Byzantine Empire collapsed, and with it the last vestiges of the Roman Empire.