Unlike the wall of a tower this was just a retaining wall cannonballs were expected to pass through this and be absorbed by a greater thickness of hard-packed earth or rubble behind. Surviving examples of bastions are usually faced with masonry. This allows more cannons to be mounted and provided enough space for the crews to operate them. This eliminated dead ground making it possible for the defenders to fire upon any point directly in front of the bastion.īastions also cover a larger area than most towers. In contrast to typical late medieval towers, bastions (apart from early examples) were flat-sided rather than curved. These ideas were further developed and incorporated into the trace italienne forts by Sébastien Le Prestre de Vauban, that remained in use during the Napoleonic Wars.Ī bastion in the Komárno Fortress (Slovakia).

To augment this change they placed v-shaped outworks known as ravelins in front of the bastions and curtain walls to protect them from direct artillery fire. The resulting construction was called a bolwerk. ĭuring the Eighty Years War (1568–1648) Dutch military engineers developed the concepts further by lengthening the faces and shortening the curtain walls of the bastions. This was exemplified by the campaigns of Charles VII of France who reduced the towns and castles held by the English during the latter stages of the Hundred Years War, and by the fall of Constantinople in 1453 to the large cannon of the Turkish army. One of the semi-circular bastions at Deal Castle, a Device Fort on the south coast of Englandīy the middle of the 15th century, artillery pieces had become powerful enough to make the traditional medieval round tower and curtain wall obsolete.

The last bastion polygon