Construction of the
Cottonera Lines began in 1670, but work was suspended ten years later due to a lack of funds. By this time, the bastioned enceinte was complete, but other crucial parts such as cavaliers, ravelins, the ditch, the glacis and the covertway had not yet been built. In the early 18th century, some efforts were made to complete the lines, although they still lacked some crucial elements. In 1724, San Salvatore Bastion, the northernmost bastion of the Cottonera Lines and the closest to the city of
Birgu, was converted into a
retrenched fort by French military engineers. The fort has two demi-bastions linked by a curtain wall, all of which are surrounded by a ditch. A parade ground is located in the centre of the fort. The fort remained in use by the British in the 19th and 20th centuries. From 1824, it was used as a
prisoner-of-war camp for Turkish prisoners during the
Greek War of Independence. It became a POW camp once more when it housed German prisoners in
World War I. Between May and July 1940, some Maltese who were believed to be supporters of
Italian irridentism, including future Prime Minister
Enrico Mizzi, were interred within the fort. 43 of the internees were later exiled to
Uganda, but were allowed to return in 1945. During
World War II, the fort became a kerosene depot. The depot exploded when the fort was bombed by Italian aircraft on 25 October 1941. ==Present day==