In the 15th century, during the age of gunpowder when the cannon came to dominate the battlefield, a new style of fortification evolved in Europe. Roughly resembling the shape of a star, these fortifications had many triangular bastions, specifically designed to cover each other, and a wide ditch. In order to counteract the cannon balls, defensive walls were made lower and thicker and were protected by gently sloping banks of earth called glacis in front of ditches so that the walls were almost totally hidden from horizontal artillery fire. The new fortification became so popular that the design was swiftly adopted by other nations as far as India and Japan.

Fort Bourtange is such a star fort located in the village of Bourtange, Groningen, Netherlands. It was built in 1593 under the orders of William the I of Orange, to control the only road between Germany and the city of Groningen, which was controlled by the Spaniards during the time of the Eighty Years' War.

Photo credit