Then, as now, the size of the gun crew varied with the size of the gun. The earliest gun crews, however, included many more highly trained artisans than do modern gun crews. The crew not only had to mix its own gunpowder on the spot, but had to be skilled in the repair of their gun, and in the arcane art of aiming the piece in the era before scientific ballistics . The smallest cannon would have a crew of two or three "artisans" and a few others to handle the animals who hauled the gun and equipment. The largest guns, like the monsters used at the siege of Constantinople in 1453, had crews of nearly a hundred men (counting all the servants, teamsters, and gofers along with the real experts).