Cottonera Lines

The Cottonera Lines, also known as the Valperga Lines, are a line of fortification in Cospicua and Birgu, Malta. They were built in the 17th and 18th centuries to form the outer defences of the Three Cities of Birgu, Senglea and Cospicua. They surrounded an earlier line of fortifications, known as the Santa Margherita Lines.

History
In 1638, construction of Santa Margherita Lines began around the land fronts of Birgu and Senglea. Works stopped soon after due to a lack of funds, and the lines remained unfinished.

In 1669, fears of an Ottoman attack rose after the fall of Candia, and a new line of fortifications was proposed to encircle both the Birgu and Senglea land fronts, as well as the unfinished Santa Margherita Lines. The new line was named the Cottonera Lines after the reigning Grand Master, Nicolas Cotoner. It was designed by the Italian engineer Antonio Maurizio Valperga, who also modified the Floriana Lines and some other fortifications of the Grand Harbour. The Cottonera Lines were meant to accommodate up to 40,000 people and their animals within their circumference.

Construction of the Cottonera Lines began in August 1670. Work was suspended due to a lack of funds in 1680. By this time, the bastioned enciente was complete and parts of the ditch had been excavated, but other crucial parts such as cavaliers, ravelins, the glacis and the covertway had not yet been built.

In the early 18th century, some efforts were made to complete both the Cottonera and the Santa Margherita Lines. Gunpowder magazines were built on St. James and St. Clement Bastions, while Fort San Salvatore was built on St. Salvatore Bastion. However, the ditch was not completed while the outworks and cavaliers were never built.

During the French blockade of 1798–1800, the lines were held by the French. The Maltese insurgents who had rebelled against them built an entrenchment around the Cottonera Lines and the other fortifications in the harbour area. A number of batteries and lookout posts, such as Tal-Borg Battery and Windmill Redoubt, were also built in the vicinity. Meanwhile, the French bombarded the Maltese in Żabbar.

The British modified the lines in the 19th century with the construction of St. Clement's Retrenchment, which connected the Cottonera Lines with the Santa Margherita Lines. Later on, Valperga Bastion and St. Paul's Curtain were demolished to make way for an extension of the Malta Dockyard.

Layout
The Cottonera Lines consist of the following bastions and curtain walls (going clockwise from Kalkara Creek to French Creek): Today, St. Laurence Demi-Bastion to Notre Dame Curtain fall within the limits of Birgu, while Notre Dame to St. Paul Bastions fall within the limits of Cospicua.
 * St. Laurence Demi-Bastion – a two-tiered demi-bastion linking the Cottonera Lines to the Birgu Land Front. Its lower part was damaged in World War II, and its upper part now houses a school.
 * San Salvatore Curtain – curtain wall between St. Laurence Demi-Bastion and San Salvatore Bastion. It contains San Salvatore Gate and two modern breaches.
 * San Salvatore Bastion – a pentagonal bastion retrenched with Fort San Salvatore, which was built in 1724.
 * St. Louis Curtain – curtain wall between San Salvatore and St. Louis Bastions. It contains the blocked-up St. Louis Gate.
 * St. Louis Bastion – a pentagonal bastion containing a World War II-era machine gun post, a 19th century cemetery and a private orchard.
 * St. James Curtain – curtain wall between St. Louis and St. James Bastions. It contains the blocked-up St. James Gate.
 * St. James Bastion – a pentagonal bastion, containing a gunpowder magazine which was later converted into a chapel. It now forms part of the grounds of St. Edward's College.
 * Notre Dame Curtain – curtain wall between St. James and Notre Dame Bastions. It contains Notre Dame Gate (the lines' main gate) and two modern breaches. It was originally protected by a ditch and tenaille, but these no longer exist.
 * Notre Dame Bastion – a pentagonal bastion, containing a 19th century redoubt.
 * an unnamed curtain wall between Notre Dame and St. Clement's Bastions. It was heavily altered in the 19th century when it was incorporated into St. Clement's Retrenchment, which links the Cottonera Lines to the Santa Margherita Lines. It is protected by a tenaille.
 * St. Clement's Bastion – a pentagonal bastion which was heavily altered in the 19th century when it was incorporated into St. Clement's Retrenchment. It contains a demi-bastioned retrenchment, a gunpowder magazine and a World War II-era anti-aircraft battery with a control station and four concrete emplacements.
 * St. Clement's Curtain – curtain wall between St. Clement's and St. Nicholas Bastions. It contains the walled-up St. Clement Gate.
 * St. Nicholas Bastion – a pentagonal bastion containing a casemated battery and a barrack block.
 * St. Nicholas Curtain, also known as Polverista Curtain – curtain wall between St. Nicholas and St. John Bastions. It contains a modern arched opening.
 * St. John Bastion – a pentagonal bastion containing a casemated battery and a World War II-era machine gun post. Housing estates were built in its piazza in the 1960s.
 * St. John Curtain – curtain wall between St. John and St. Paul Bastions. It contains the walled-up St. John Gate.
 * St. Paul Bastion – a pentagonal bastion containing casemates which were eventually converted into barracks. In the 19th century, it was linked to the Corradino Lines. A tunnel allowing vehicular access to the Three Cities now cuts into bastion's base.
 * St. Paul Curtain – curtain wall between St. Paul and Valperga Bastions. It contained St. Paul Gate, also known as Porta Haynduieli. The curtain and gate were demolished in the 19th century to make way for the extension of the dockyard.
 * Valperga Bastion – a large demi-bastion which was demolished in the 19th century to make way for the extension of the dockyard.