Polygonal Forts was layout of a fort that developed from the Bastion System of Vauban and others. The Polygonal layout originated in France and was further developed in Germany in the first half of the 18th Century. The polygonal fort, often with five or straight sides, proved ideal for mounting and resisting the new artillery and was to be used well into the 20th Century.
Many of the Royal Commission Forts built in the United Kingdom between 1860 and 1870 followed a polygonal layout. It is believed that Sir William Francis Drummond Jervois, who helped design many of the Royal Commission Forts was inspired by Fort Tigne in Malta. Malta was under British control and had been carefully studied by the Royal Engineers. It is believed to have been one of the earliest polygonal forts, although built by the Knights of St John.
