Back in the Bad Old Days, mules were employed by the British Army to pull the guns of medium artillery batteries -too heavy for horses, but light enough that the use of bullocks or elephants would have been excessive.

In particular, mules were favoured for the 'screw-guns'. This was a type of howitzer, designed to be disassembled for transport, then assembled on-site. The idea was to get the gun to a high enough spot for it to do damage to the enemy while being nearly unreachable itself. Mules, with their strength, endurance and ability to pick out a path in the most unpromising of terrain, were ideal for the task of carrying the broken-down weapons.

As me and my companions were scrambling up a hill,

The path was lost in rolling stones, but we went forward still;

For we can wriggle and climb, my lads, and turn up everywhere,

Oh, it's our delight on a mountain height, with a leg or two to

spare!

Good luck to every sergeant, then, that lets us pick our road;

Bad luck to all the driver-men that cannot pack a load:

For we can wriggle and climb, my lads, and turn up everywhere,

Oh, it's our delight on a mountain height, with a leg or two to

spare!

(Kipling: "Parade-Song of the Camp Animals")