By 1326, gunpowder artillery had arrived in Europe. These first, arrow-firing cannons were perfectly serviceable, but small and simple. Little more than a century later, in 1453 the mighty walls of Constantinople were being battered down by gunpowder weapons, and in 1494 Charles VIII launched the Italian Wars, bringing a train of mobile artillery on campaign for the first time. This was the era of great, prestigious siege guns, such as Mons Meg and...