The Tsar Cannon is a one-off cannon piece cast in 1586 in Russia by famed Cannon maker Andrey Chokhov. A display piece, located by the Kremlin in Moscow, the Tsar Cannon has only ever been fired once but its performance is unknown.
The Tsar Cannon is made entirely from bronze, comprising simply of a barrel measuring 19.5ft (5.9m) and 3.9ft (1.2m) in diameter. This is sat on an ornamental cast iron carriage, cast in 1835 (which is not considered part of the Tsar Cannon), with the barrel featuring eight cast rectangular brackets for transportation. The ratio of the barrel's bore the barrel length would technically make the Tsar Cannon a mortar rather than a cannon.
The Tsar Cannon's ornamental appearance helps to suggest that it was never designed for combat. The cannon is decorated with various images a markings, most prominent of which is the equestrian image of Tsar Feodor Ioannovich located near the muzzle of the barrel. This is added to the fact that, for its size, the amount of bronze required to cast the Tsar Cannon cost the Tsar a small fortune, further reinforces the idea that the Tsar Cannon was designed to intimidate potential invaders rather than fire against them.
The Tsar Cannon was cast to accept a caliber of 35in (0.89m). This, at the time, would have meant it could fire stone cannon balls (the common ammunition for large cannon at the time) but it is far more likely that, on the one occassion that it was fired, that the ammunition used was grape shot.
Legend has it that the ornamental, hollow, cannon balls placed next to the Tsar Cannon were made in St Petersburg as a joke, being too big to fit the Tsar Cannon. This demonstrates the traditional, friendly rivalry between the two cities. These balls were cast at the same time as the carriage at the Berdt's Factory in St Petersburg.
The Tsar Cannon has, as has been mentioned, been fired only once. Its performance is unknown but the Tsar Cannon is, nonetheless, recorded as the larget bombard by caliber by the Guiness Book of World Records. It must be noted that the Tsar Cannon effectively referres to the barrel only, as the carriage has been changed many times over its history. It was cast on the orders of Tsar Feodor Ioannovich by the renowned Russian Cannon manufacturer Andrey Chokhov.
The Tsar Cannon has been moved, despite its evident large size, around Moscow on more than one occasion. Its original location was in Red Square (mounted on an inclamated, ornamental frame) in Moscow, next to the Palace of Skulls, a position which suggests that the Tsar Cannon was intended to defend the Kremlin. By 1706 the Tsar Cannon had been move to the Kremlin Arsenal, mounted on a wooden carriage (that would be burnt during the fire of Moscow in 1812). Despite Napoleon Bonaparte's consideration to remove the Tsar Cannon to Paris (as a trophey of the French conquest of Moscow in the early 19th century) the Tsar Cannon would be taken, by 1860, to its current location Ivanovskaya Square, Moscow.
During the Second World War some of the demoralised Red Army troops were recorded as naming the Tsar Cannon "Stalin's Shaft" referring to his leadership style (leading with an iron fist). This reference quickly became taboo, with those that said the words "Stalin's Shaft" mysteriously being transferred to the Western front in the following hours.
The Tsar Cannon has been restored several times in its existence, the last time being in the 1970's and finished in 1980. The Tsar Cannon was studied at this time when it was found that some residue from a previous firing had been discovered inside the barrel. However it was impossible for the researchers to date when the powder residue was used.