It is a monument of Russian artillery casting art, cast in bronze in 1586 in Moscow, by the Russian master bronze caster Andrey Chokhov. Mostly of symbolic impact, it was never used in a war.
During the French invasion of Russia, although Napoleon Bonaparte considered removing it to France as a war trophy.
The gun was meant to shoot 800 kg stone grapeshot rather than true, solid cannonballs.
Its bronze-cast barrel has an internal diameter of 35"
The cannon-style gun carriage, added in 1835, is purely decorative. This weapon was never intended to be transported on or fired from this gun carriage.
The 2000 pound cannon balls located in front of the Tsar Cannon were produced in 1834 as a decoration, too large to have been used in the cannon.
According to legend, the cannonballs were manufactured in St. Petersburg, and were intended to be a humorous addition and a symbol of the friendly rivalry between Moscow and St. Petersburg.
the next largest super cannon was the The Dardanelles Gun, made before Columbus sailed the Atlantic
a 15th-century super-sized bombard siege cannon, designed and built in 1464 by Turkish military engineer Munir Ali, which saw action in the 1807 Dardanelles Operation, it has a range of a mile
The breech in this cannon is shorter and slightly smaller diameter than the chase. Both parts are cast with prominent double mouldings at either end which are joined longitudinally by sixteen crosspieces to form an equal number of sockets for the insertion of the levers used in screwing or unscrewing the two parts.
The Dardanelles Operation was the Royal Navy's unsuccessful attempt to impose British demands on the Ottoman Empire as part of the Anglo-Turkish War (1807-1809).
British ships were attempting to deter the Ottomans from entering into a war with Russia, ensure freedom of movement for British ships, and hopefully free-up shipping lanes.
The operation occurred only two years after the Royal Navy had triumphed at the Battle of Trafalgar.
In 1866, on the occasion of a state visit, Sultan Abdülâziz gave the Dardanelles Gun to Queen Victoria as a present.
the two pieces screw together, fire grapeshot, the barrel has a bore of 24.5 inches
As one of the larger and well documented surviving medieval cannons, Mons Meg stands in pride of place at Edinburgh Castle and in its history.
Constructed around 1449 in Mons, part of what is now modern day Belgium, at the request of Duke Philip the Good of Burgundy, the bombard was intended as a wedding present to King James II of Scotland, who, in 1457 married Duke Philips' great niece, Mary of Gueldres.
With an impressive rate of fire of 8 shots a day (it had to be cooled and cleaned after each shot), it had a theorical range of 2.5 miles although it was used at 1.25
Next, and 4th largest fired cannon in human history
The possibly the least cared for, most neglected, and farthest from a historical appreciative culture that would take the time and money to properly make a respectable monument for it to adorn.
In the far south of India, long distances from anywhere in India I've ever heard of, Bombay and Calcutta, is an ancient kingdom of Thanjavur, who used Dutch know how (Dutch East Indies Company? ) to forge, not cast, a massive 22 ft long cannon that was constructed by rings and steel strips.
the cannon is named Beerangi Medu, and is mounted at Keela Alankam in Thanjavur town
British photographer Captain Linnaeus Tripe documented the stunning cultural artifacts of Burma and South India in the mid-19th century with an unprecedented series of photos.
the Dutch East Indies Company was established on in 1602, as a company to trade with North Eastern India from which 50% of textiles and 80% of silks were imported from its most developed region currently known as Bangladesh and West Bengal, India.
I may be wrong, but from trying to get info from sites that aren't simply written for enjoyment of English speaking Americans. Every god damn thing is in metric for one thing, and some measurements make no damn sense. For a scientific analysis that goes on in great detail for pages, see http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.692.5714&rep=rep1&type=pdf
So, it seems to have been 22 feet long, weigh 24 tons, and shoot a 2200 pound iron cannon ball, or 660 pound stone cannon ball, from a 25 foot high fort wall, towards the eastern gate / rampart of the Thanjuvar Fort.
according to https://dailytimewaster.blogspot.com/2013/11/i-wonder-where-it-is-now.html they laid out a 2 mile long black power trail that when lit took 40 minutes to burn, simply to give the military the distance from it to protect themselves and their hearing. Other earlier cannons had water tanks nearby for the fuse lighter to jump into for isolation from the whole sound, heat, and pressure waves: https://twitter.com/ArchaeoNomad/status/1023809526758174721
The 2 mile long black powder trail is probably based on this "The Western Mail" account in the 13 July 1940 edition
Inside, it is made using 43 long iron plates and the outer of 94 iron rings. To lift the cannon eight rings were wrapped around it for a crane to get ropes or chains for the lifting.