Since the pre-Roman period, a fortified settlement has existed on the hill where Carcassonne now stands. In its present form it is an outstanding example of a medieval fortified town, with its massive defences encircling the castle and the surrounding buildings, its streets and its fine Gothic cathedral. Carcassonne is also of exceptional importance because of the lengthy restoration campaign undertaken by Viollet-le-Duc, one of the founders of the modern science of conservation.
Founded during the Gallo-Roman period, the citadel derives its reputation from its 3 kilometres long double surrounding walls interspersed by 52 towers. The town has about 2,500 years of history and has seen the Romans, Visigoths, Saracens and Crusaders. At the beginning of its history it was a Gaulish settlement then in the 3rd century A.D., the Romans decided to transform it into a fortified town. The Roman defences were in place by 333 AD. The original walls were supported by between 34 and 40 towers, spaced from 18 to 30 metres apart along the curtain wall. Each tower was semicircular in plan and about 14 metres tall. There were probably four main entrances to the town.
The Gallo-Roman walls were rebuilt during the town's occupation by the Visigoths in the 5th and 6th centuries, but the original structure remained in place. After 1226, an additional line of fortifications was added outside of the Roman walls. The town was finally annexed to the kingdom of France in 1247 A.D. It provided a strong French frontier between France and the Crown of Aragon. During this period, the inner, Roman walls were largely demolished and replaced, while the new outer walls were reinforced and extended to the south. The new towers built during this work were mainly circular, but two were square. Construction continued into the reign of King Philip IV in the early 14th century.
In 1659, after the Treaty of the Pyrenees, the province of Roussillon became a part of France, and the town lost its military significance. Fortifications were abandoned and the town became one of the economic centres of France, concentrating on the woolen textile industry.
In 1849 the French government decided that the city fortifications should be demolished. This decision was strongly opposed by the local people. Jean-Pierre Cros-Mayrevieille and Prosper Mérimée, an eminent archaeologist and historian, led a campaign to preserve the fortress as a historical monument. The government later reversed its decision and in 1853 restoration work began. The architect Eugène Viollet-le-Duc was charged with renovating the fortress. Viollet-le-Duc's work was criticised during his lifetime as inappropriate to the climate and traditions of the region. After his death in 1879, the restoration work was continued by his pupil, Paul Boeswillwald, and later by the architect Nodet.
The citadel was restored at the end of the 19th century and in 1997 it was added to UNESCO's list of World Heritage Sites.References:
Kristiansten Fortress was built to protect the city against attack from the east. Construction was finished in 1685. General Johan Caspar von Cicignon, who was chief inspector of kuks fortifications, was responsible for the new town plan of Trondheim after the great fire of 18 April 1681. He also made the plans for the construction of Kristiansten Fortress.
The fortress was built during the period from 1682 to 1684 and strengthened to a complete defence fortification in 1691 by building an advanced post Kristiandsands bastion in the east and in 1695 with the now vanished Møllenberg skanse by the river Nidelven. These fortifications were encircled by a continuous palisade and thereby connected to the fortified city. In 1750 the fortress was modernized with new bastions and casemates to protect against mortar artillery.