The fortifications of Constantinople in the 15th century
Prior to the siege of Constantinople it was known that the Ottomans had the ability to cast medium-sized cannons, but the range of some pieces they were able to put to field far surpassed the defenders' expectations. One cannon was 9 m long, and able to fire 750 kg over the distance of 2 km. The Greeks called it the Basilica cannon (the royal gun). Instrumental to this Ottoman advancement in arms production was a somewhat mysterious figure by the name of Orban.
The Dardanelles Gun, cast in 1464 and based on the Orban bombard.
The origins of Orban remains uncertain. According to some scholars he was Hungarian; John Julius Norwich, in A Short History of Byzantium (1997), suggest he was German. Laonicus Chalcondyles (c. 1423–1490), a Byzantine Greek scholar from Athens who lived in the time of siege, in his work Proofs of Histories says that Orban was a 'Dacian' - '[...] but the Emperor had a Dacian cannon founder named Orban, creator of weapons and tools for breking the walls. [...] Orban was a man between two ages, with blond mustache and rosy-cheeked'. Chalcondyles named in his works the Romanians as 'Dacians'. 'Orban' is indeed a Hungarian name, but it is frequent also in Belgium and Holland; spelled 'Urban', it has a Latin ascendancy. Probably, Orban was a Transylvanian-born Hungarian or Romanian, but the hypothesis remains unverified.
Mehmed II by Bellini
The master founder initially tried to sell his services to the Byzantines, who were, however, unable to secure the funds needed to hire him. Orban then left Constantinople and approached Mehmed II. Accordingly, Orban's arrival at Edirne must have seemed providential. The sultan welcomed the master founder and questioned him closely. Mehmed asked if he could cast a cannon to project a stone ball large enough to smash the walls at Constantinople. Orban's reply was emphatic: 'I can cast a cannon of bronze with the capacity of the stone you want. I have examined the walls of the city in great detail. I can shatter to dust not only these walls with the stones from my gun, but the very walls of Babylon itself'. Mehmed ordered him to make the gun. Given abundant funds and materials, the engineer built the gun within three months at Adrianople, from which it was dragged by sixty oxen to Constantinople. In the meantime, Orban also produced other cannons instrumental for the Turkish siege forces.
Orban's cannon had several drawbacks, however: it could only be fired seven times a day; it took three hours to reload; the cannon balls were in very short supply; after each shot, crews soaked the barrel in warm oil to prevent cold air from penetrating and enlarging the fissures; and the cannon is said to have collapsed under its own recoil after six weeks (this fact however is disputed, being only reported in the letter of Archbishop Leonardo di Chio and the later and often unreliable Russian chronicle of Nestor Iskander). Having previously established a large foundry approximately 150 miles away, Mehmed now had to undergo the painstaking process of transporting his massive pieces of artillery. Orban's giant cannon was said to have been accompanied by a crew of 60 oxen and over 400 men (Doukas or Dukas, The Turkish-Byzantine History, (1341-1462)).
The Ottoman army and the Basilica cannon
And when it had caught fire, faster than you can say it, there was first a terrifying roar and a violent shaking of the ground beneath and for a great distance around, and a din such as has never been heard. Then, with a monstrous thundering and an awful explosion and a flame that illuminated everything round about and scorched it, the wooden wad was forced out by the hot blast of dry air and propelled the stone ball powerfully out. Projected with incredible force and power, the stone struck the wall, which it immediately shook and demolished, and it was itself shattered into many fragments, and the pieces were hurled everywhere, dealing death to those standing nearby.
The bombard technology from which Orban drew had been established between 1400 and 1450 in Western European siege warfare, with some pieces like the Dulle Griet, Mons Meg and the Pumhart von Steyr still extant from the period. He, along with an entire crew, is assumed to have been killed during the siege by one of his superguns exploding, then not an unusual occurrence (Volker Schmidtchen, 1977). One of a growing band of technical mercenaries who plied their trade across the Balkans, he offered to the two Emperors one of the most highly prized skills of the age: the ability to cast large bronze guns. The Orban's cannon symbolized the end of outmoded medieval techniques of castle construction and siege warfare and opened a terrible new chapter in military history. The use of massed artillery bombardment would prevail.