A late-16th-century illustration of cannon used in a siege, with a row of gabions, cylinders filled with soil or sand, in front of them for protection. In the medieval era, they were made from wicker with open tops and bottoms, so that they would be light and could be carried relatively conveniently in the ammunition train, particularly if they were made in several diameters to fit one in another.Illustration: Agostino Ramelli; Restoration: Lise Broer