Lines of Torres Vedras

The Lines of Torres Vedras were lines of forts built in secrecy to defend Lisbon during the Peninsular War. Named after the nearby town of Torres Vedras, they were ordered by Arthur Wellesley, Viscount Wellington, constructed by Portuguese workers between November 1809 and September 1810, and used to stop Masséna's 1810 offensive.

Genesis

After his troubling Spanish experience at the Battle of Talavera, Wellington decided to strengthen Portugal. He used a report of Colonel Vincent, ordered by Junot in 1807, describing the excellent defensive capacities in the region nearby Lisbon. There is some work that the study by Major Neves Costa influenced Wellington's decision to construct the Lines, but in fact his plans pre-date Costa's study [The Lines of Torres Vedras: The Cornerstone of Wellington's Strategy in the Peninsular War 1809-1812, John Grehan, Spellmount] . He was also inspired by the Martello Towers along the British Channel coast. Wellington ordered the building of the Lines of Torres, as a system of fortifications blockhouses, redoubts, ravelins, cuts of natural relief, etc. The work began in the Autumn of 1809 and the first line was finished one year later. Construction of the lines continued and in 1812, 34,000 men were still working on them.

The work was supervised by Lieutenant-Colonel Sir Richard Fletcher, assisted by Major John Jones, 11 British officers, two KGL officers and four Portuguese Army engineers. The cost was around £100,000, one of the least expensive but most remunerative military investments in history.

Effects

The Anglo-Portuguese army was forced to retreat to The Lines after the Battle of Buçaco. The French (under Marshal André Masséna) discovered upon their arrival at The Lines a barren land (under the scorched earth policy) and an enemy behind an impenetrable defensive position. Masséna's forces arrived at the Lines on 11 October and shortly afterwards stormed Sobral de Monte Agraço but were repulsed in the attempt to assault of Forte de Alqueidão (Alqueidão Fort), a second bigger and better equipped redoubt.

After attempting to wait out the enemy, Masséna was forced to order a French retreat to Spain, starting on the night of 15 November 1810, to re-supply and reinforce his army. Marshal Masséna began his campaign with his army (l'Armée de Portugal) at 65,000 strong. By the time he reached Torres Vedras, he had 61,000 men (after losing 4,000 at the Battle of Buçaco). When he reached Spain, he had lost 25,000 men (including those lost at Buçaco). One of the coldest winters Portugal had ever seen, hit Portugal and killed many of the French forces. They were also hit by severe illness and disease killing the soldiers in their thousands. The human cost was great for the population, because of the privations they supported. It is estimated that between October 1810 and March 1811 about 50,000 Portuguese died of hunger or disease.

The Allies were reinforced by fresh British troops in 1811 and renewed their offensive. They left The Lines and did not return for the rest of the Peninsular War.

Description

The three lines of Torres Vedras had forts strategically placed in the top of hills, controlling the roads to Lisbon and using the natural obstacles of the land.The first line, with an extension of 46 km, binds Alhandra to the estuary of the Sizandro river. The second line, 13 km to the south, has 39 km and binds the Póvoa de Santa Iria to Ribamar. The third line consisted of a defensive perimeter with 3 km, from Paço de Arcos to the Tower of Junqueira, protecting a beach of embarcation (St. Julian's) about 40 km to the south of the second line.

In seven months, 108 forts and 151 redoubts were built, with ravelins, detached batteries, etc. The three lines were furnished with 1,067 pieces of artillery and provided with 68,665 men, one of the most efficient systems of field blockhouses in military history. Behind them was the field army of 50,000 Anglo-Portuguese regulars, able to manoeuvre against the invaders.

The fourth line was built south of the Tagus in the Almada highs to hinder an eventual invasion coming from south, with an extension of 8,000 yards (7.3 km): It had 17 redoubts and covered trenches, 86 pieces of artillery, defended by marines, and orderlies of Lisbon, for a total of 7,500 men.

Substantial portions of the lines still survive today, albeit heavily decayed.

Efficiency and cohesion

The efficiency and cohesion of the Lines was based on five points:

1) Redoubts of artillery with Portuguese artillerymen, commanded by major-general José António Rosa, and specialized to fire into preset zones, where the enemy attack was expected;Both lines had more than 80 km. The first line had 534 artillery pieces.

2) Military roads to cover the rear of the lines and allowing an extraordinary mobility of forces. In September 1810, the field army had some 66,598 regular soldiers. Including the Ordenanças and Milicias, it had 77,690 men.

3) A Semaphore system introduced by the British Navy allowing a message to be sent around the lines in 7 minutes; or from the HQ to any point in 4 minutes.The signal system had five stations:
* Redoubt n.30 close to the ocean (Ponte do Rol)...
* The great redoubt of Torres Vedras (Fort St Vincent)
* Monte do Socorro close to Pêro Negro, Wellington’s headquarters
* Monte Agraço
* Alhandra, by the Tejo.

4) Secrecy - The building of the lines took, surprisingly, only 7 months. Lisbon became a peninsula defended by a most efficient system of blockhouses. Everything was preserved as a secret, whose maintenance is as surprising as the building of the lines. It is said that when Masséna was first confronted by the Lines, he asked his staff why they had not known about them in advance. "Wellington has made them", replied someone. Masséna shouted, "To the Devil with you! Did Wellington make the mountains?"

5) The "scorched earth" policy - North of the lines everything that could supply the invading army was collected, hidden or burnt. A vast tract of land was deserted and perhaps 200,000 inhabitants of the neighbouring districts of the lines were relocated inside the lines. That the French were able to campaign in their vicinity at all was a remarkable feat, according to Wellington: [Gates, p.237-238]

Notes

ee also

* Trench warfare

Further reading

NORRIS, A.H. e BREMNER, R. W., The lines of Torres Vedras. The first three lines and fortifications south of the Tagus, Lisboa, The British Historical Soc. of Portugal, 1986.

External links

* [http://www.remuseum.org.uk/biography/rem_bio_fletcher.htm Royal Engineers Museum] - Lt Col Sir Richard Fletcher (1768-1813) Architect of the Lines of Torres Vedras
* [http://www.remuseum.org.uk/campaign/rem_campaign_peninsular.htm#lines Royal Engineers Museum] The Engineers and the Peninsular War (1808-14)-Construction of the Lines of Torres Vedras