A fortification is a military construction designed for the defense of territories in warfare, and is used to establish rule in a region during peacetime. The term is derived from Latin fortis ("strong") and facere.
A bastion or bulwark is a structure projecting outward from the curtain wall of a fortification, most commonly angular in shape and positioned at the corners of the fort. The fully developed bastion consists of two faces and two flanks, with fire from the flanks being able to protect the curtain wall and the adjacent bastions. Compared with the medieval fortified towers they replaced, bastion fortifications offered a greater degree of passive resistance and more scope for ranged defence in the age of gunpowder artillery. As military architecture, the bastion is one element in the style of fortification dominant from the mid 16th to mid 19th centuries.
The fortifications of Portsmouth are extensive due to its strategic position on the English Channel and role as home to the Royal Navy. For this reason, Portsmouth was, by the 19th century, one of the most fortified cities in the world. The fortifications have evolved over the centuries in response to changes in tactics and technology and the area defended has increased. While the first defences focused on Portsmouth harbour, in step with the fortifications of Gosport, later defensive structures protected the whole of Portsea Island and an increasing distance inland. At the same time, the fortifications of Portsmouth and Gosport became part of the wider fortifications of the Solent. Old Portsmouth, on the southwest corner of Portsea Island, has been walled for much of its history.
Shoreham Redoubt is a historical military defensive structure and scheduled monument at the entrance to Shoreham harbour, at the mouth of the River Adur in West Sussex, England. It was planned in the 1850s during a period of political alarm in the United Kingdom. Construction of the fort was completed in June 1857 at a cost of £11,685. The design is similar to that of Littlehampton Fort, which had been built in 1854.
Littlehampton Redoubt, usually known as Littlehampton Fort, was built in 1854 to protect the entrance to the River Arun at Littlehampton on the south coast of England, against possible attack by the French under the Emperor Napoleon III. There had been a previous battery on the east bank of the river, but the new fort was built on the west bank. It consisted of a platform from which cannon could sweep the harbour mouth, with a barracks behind and a surrounding defensive ditch and wall. The fort was an innovative military structure, incorporating the new feature of a Carnot wall. Its active use as a fort was short at only about 20 years, owing to technical changes in armaments, but it was a precursor of the later Palmerston Forts and therefore is NOT the First Palmerston Fort as has been alleged. The Palmerston Forts were built after the 1860 commission. Littlehampton Fort is now in a ruinous and overgrown state but largely protected by the Ivy that now grows over the walls.
Fort Cumberland is a pentagonal artillery fortification erected to guard the entrance to Langstone Harbour, east of the Dockyard of Portsmouth on the south coast of England. It was sited to protect the Royal Navy Dockyard, by preventing enemy forces from landing in Langstone Harbour and attacking from the landward side. Fort Cumberland is widely recognised as the finest example of a bastion trace fort in England. It is a scheduled monument and a Grade II* listed building
The Western Heights of Dover are one of the most impressive fortifications in Britain. They comprise a series of forts, strong points and ditches, designed to protect the country from invasion. They were created in the 18th and 19th centuries to augment the existing defences and protect the key port of Dover from both seaward and landward attack; by the start of the 20th century Dover Western Heights was collectively reputed to be the 'strongest and most elaborate' fortification in the country. The Army finally withdrew from the Heights in 1956–61; they are now a local nature reserve.
The Royal Commission on the Defence of the United Kingdom was a committee formed in 1859 to enquire into the ability of the United Kingdom to defend itself against an attempted invasion by a foreign power, and to advise the British Government on the remedial action required. The appointment of the Commission had been prompted by public concern about the growing military and naval power of the French Empire and was instigated by the Prime Minister, Henry Temple, 3rd Viscount Palmerston, who came to be closely associated with the project. In the following year, the Commission's report recommended a huge programme of fortification to defend the country's arsenals and naval bases. Many of the recommendations were acted upon; however, the great expense, the length of time taken to complete the various works and their perceived usefulness were all subjects of critical political, press and public debate.
Pendennis Castle is an artillery fort constructed by Henry VIII near Falmouth, Cornwall, England between 1540 and 1542. It formed part of the King's Device programme to protect against invasion from France and the Holy Roman Empire, and defended the Carrick Roads waterway at the mouth of the River Fal. The original, circular keep and gun platform was expanded at the end of the century to cope with the increasing Spanish threat, with a ring of extensive stone ramparts and bastions built around the older castle. Pendennis saw service during the English Civil War, when it was held by the Royalists, and was only taken by Parliament after a long siege in 1646. It survived the interregnum and Charles II renovated the fortress after his restoration to the throne in 1660.
A caponier is a type of defensive structure in a fortification. Fire from this point could cover the ditch beyond the curtain wall to deter any attempt to storm the wall. The word originates from the French caponnière, meaning "chicken coop".
A bastion fort or trace italienne is a fortification in a style that evolved during the early modern period of gunpowder when the cannon came to dominate the battlefield. It was first seen in the mid-fifteenth century in Italy. Some types, especially when combined with ravelins and other outworks, resembled the related star fort of the same era.
The Séré de Rivières system was an ensemble of fortifications built from 1874 along the frontiers, ridges and coasts of France. The fortifications were named after their architect, Brigadier-General Raymond Adolphe Séré de Rivières. The fortresses were obsolescent by 1914 but were used during the First World War.
In military engineering, a ditch is an obstacle designed to slow down or break up an attacking force, while a trench is intended to provide cover to the defenders. In military fortifications the side of a ditch farthest from the enemy and closest to the next line of defence is known as the scarp while the side of a ditch closest to the enemy is known as the counterscarp.
The Thiers wall was the last of the defensive walls of Paris. It was an enclosure constructed between 1841 and 1846 and was proposed by the French prime minister Adolphe Thiers but was actually implemented by his successor. The 33 kilometres (21 mi) long wall and ditch made a complete circuit around the city as it stood at the time of the July Monarchy. It was bombarded by the Prussian Army during the Franco-Prussian War, captured by government troops during the Paris Commune and refortified at the start of the First World War. However, by then it had become obsolete as a fortification and was a barrier to the expansion of the city. The area immediately outside of it, known as "the zone", had become a shanty town. The wall was demolished in the interwar period; its path today can be traced by the Boulevards of the Marshals which originally ran just behind the fortifications and by the Boulevard Périphérique which was later built just outside. A few remnants of the wall can still be seen.
The North Bastion, formerly the Baluarte San Pablo was part of the fortifications of Gibraltar, in the north of the peninsula, protecting the town against attack from the mainland of Spain. The bastion was based on the older Giralda tower, built in 1309. The bastion, with a mole that extended into the Bay of Gibraltar to the west and a curtain wall stretching to the Rock of Gibraltar on its east, was a key element in the defenses of the peninsula. After the British took Gibraltar in 1704 they further strengthened these fortifications, flooding the land in front and turning the curtain wall into the Grand Battery.
The counterguard is an outwork in a bastioned fortification system that usually comprises only a low rampart and which is sited in front of the actual fortress moat that runs around the bastions or ravelins. The rampart way of a counterguard is, however, so constructed and at least wide enough that it enables the positioning of guns. An additional ditch in front of it guards the work from a frontal enemy assault. The function of counterguards was to protect the higher ravelin or bastion behind it from direct fire and to delay an attack on it as long as possible. So that the counterguards and the works that they were to protect, could not come under simultaneous fire along the line of the rampart they were not allowed to run parallel to one another.
The Twydall Profile was a style of fortification used in British and Imperial polygonal forts at the end of the 19th century. The sloping earthworks employed in the Twydall Profile were intended to be quick and inexpensive to construct and to be effective in the face of the more powerful artillery and high explosive ammunition being introduced at that time. The name comes from the village of Twydall in Kent, where the first forts of this type were built.
In fortification architecture, a rampart is a length of embankment or wall forming part of the defensive boundary of a castle, hillfort, settlement or other fortified site. It is usually broad-topped and made of excavated earth and/or masonry.
A polygonal fort is a type of fortification originating in France in the late 18th century and fully developed in Germany in the first half of the 19th century. Unlike earlier forts, polygonal forts had no bastions, which had proved to be vulnerable. As part of ring fortresses, polygonal forts were generally arranged in a ring around the place they were intended to protect, so that each fort could support its neighbours. The concept of the polygonal fort proved to be adaptable to improvements in the artillery which might be used against them, and they continued to be built and rebuilt well into the 20th century.
