This list contains all types of cannon through the ages listed in decreasing caliber size. For the purpose of this list, the development of large-calibre artillery can be divided into three periods, based on the kind of projectiles used, due to their dissimilar characteristics, and being practically incommensurable in terms of their bore size:
- Stone balls: Cannon of extraordinary bore, which fired stone balls, were first introduced at the turn of the 14th to 15th century in Western Europe. Following a logic of increasing performance through size, they had evolved from small handguns to giant wrought-iron or cast-bronze bombards within a span of just several decades.
- Iron balls and shot: By the 16th century, however, a general switch from stone balls to smaller, but much more effective iron projectiles was in full swing. This and the parallel tendency towards standardized, rapid-firing cannon made the enormously costly and logistically demanding giant guns soon obsolete in the European theatre (with the exception of the odd showpiece).
- Explosive shells: In the Industrial Age, artillery was again revolutionized by the introduction of explosive shells, beginning with the Paixhans guns. Breakthroughs in metallurgy and modes of production were followed up by new experimentation with super-sized caliber weapons, culminating in the steel colossi of the two World Wars. In the post-war era, the development of extremely overpowered artillery was gradually abandoned in favour of missile technology, while heavy guns are still demanded by various arms of the service.
The list includes only cannons that were actually built, that is, cannons that existed only as concepts, ideas, proposals, plans, drawings or diagrams are excluded. Also excluded are those cannons that were only partially built (not a single complete artillery piece of the cannon type in question fully built). The list includes cannons that were completed (fully built) but did not fire even once (or there is debate/insufficient evidence about whether the cannons were ever fired). Also cannons that never were used in combat are included. Naturally, the list only includes real cannons (made from metal and meant to be fired with gunpowder and a projectile to cause major destruction) and replicas etc. (made from plastic or fiberglass, for example) and other non-real cannons (meaning those cannon-like pieces that were not meant to be fired with gunpowder and a projectile capable of causing major destruction) are excluded.
