The Lines of Torres Vedras were a line of forts in Portugal built in secrecy between November 1809 and September 1810 by Portuguese workers, under the supervision of Army Engineers.
Genesis
After his troubling Spanish experience at 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 and topographical studies by Major Neves Costa. Wellington commanded the building of the Lines of Torres Vedras, as an efficient system of blockhouses, redoubts, ravelins , cuts of natural relief, etc. The supervison was entrusted to Colonel Fletcher, assisted by Major John Jones, 11 British officers, 2 KGL officers and 4 Portuguese Army engineers. The cost was down to around £100,000, one of the less expensive but remunerative military investments in history. The human cost was great for the population, on account of the privations they supported.
The Anglo-Portugese army was forced to retreat to The Lines after the Battle of Buçaco. The French (under Marshall André Masséna) dicovered upon their arrival at The Lines a barren land (under the Scorched Earth policy) and an enemy behind an impenertrable defensive posistion. After attempting to wait out the enemy, the French were forced to retire to Spain to re-supply and reinforce their army. Marshall Masséna began his campaign with his army (l'Armee 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, they were also hit by severe illness and diease killing the soldiers in their thousands. The Allies were reinforced by fresh British troops in 1811 and renewed their offensive, leaving The Lines and not returning for the rest of the Peninsular War.
Description
The 4 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 1st line, with an extension of 46 km, binds Alhandra to the estuary of the Sizandro River. The 2nd line, 13 km to the south, has 39 km and binds the Póvoa de Santa Iria to Ribamar. The 3rd line consisted of a defensive perimeter with 3 km, from Paço de Arcos to the Tower of Junqueira, protecting a beach of embarkment (St. Julian's) about 40 km to the south of the 2nd line.
In 7 months, 108 forts and 151 redoubts were built, with revelins, 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 system of field blockhouses in military history. Behind them was the field army of 50,000 Anglo-Portuguese regulars, able to manoeuver against tne invaders.
The 4th line was built south of the Tagus in the Altos of Almada 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 troops of the navy, and orderlies of Lisbon, in a total of 7500 men.
It is considered by many to be the finest military defensive position ever created by man.
Efficiency and cohesion
- 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;
- military roads to cover the rear of the lines and allowing an extraordinary mobility of forces;
- A Signal System introduced by the British navy, a system allowing a message to be sent around the lines in 7 minutes; or from the HQ to any point in 4 minutes.
