Trunnion

[5] The gun would recoil causing the carriage to move backwards several feet but men or a team of horses could put it back into firing position.

Two significant changes were the additions of a ditch and low, sloping ramparts of packed earth (glacis) that would surround the city and absorb the impact of the cannonballs, and the replacement of round watchtowers with angular bastions.

Preexisting stronger entities, such as France or the Habsburg emperors, were able to expand their territories and maintain a tighter control over the land they already occupied.

With siege guns mounted on trunnions, stronger and larger states were formed, but because of this, struggles between neighboring governments with consolidated power began to ensue and would continue to plague Europe for the next few centuries.

[6] In mechanical engineering, it is one part of a rotating joint where a shaft (the trunnion) is inserted into (and turns inside) a full or partial cylinder.

Often used in opposing pairs, this joint allows tight tolerances and strength from a large surface contact area between the trunnion and the cylinder.