Defensive heritage mapping
Introduction
The Lines of Torres Vedras were a series of fortifications built secretly for the defense of Lisbon during the Peninsular War —so called by the British and Portuguese— or War of Independence —so called by the Spanish—, at the beginning of the century.
Its construction was ordered by the English general Arthur Wellesley, first Duke of Wellington, who commanded the British expeditionary force in Portugal. The design and construction was entrusted to Lieutenant Colonel Richard Fletcher, who was assisted by English and Portuguese officers from the Corps of Engineers. The lines were built by Portuguese workers between November 1809 and September 1810, the date on which the offensive of Marshal André Masséna paralyzed their construction.[1].
The opportunity and effectiveness of their construction was total, since the French army did not attempt to assault them. His final retreat from Portugal began when he found it impossible to penetrate such a well-conceived defensive line, which amounted to a decisive military victory achieved without battle and with few shots and casualties.
Brief description
Although at first an attempt was made to build a single line of defenses from the Tagus, in the east, to the Atlantic Ocean, in the west, in the end four lines were built, two major and two minor:
• - A first further north, at the height of Torres Vedras, from where the lines take their name, and which was the only one that faced the French invaders.
• - A second further south, near Mafra. At first it was the only one that was going to be built, but the delay in the French invasion and the abundance of Portuguese labor allowed it to be reinforced by the first.
• - A third in Oeiras, on the outskirts of Lisbon, around the fort of San Julián, exclusively dedicated to protecting the re-embarkation of the English forces, if it became necessary.
• - A fourth, on the other side of the river, just in front of Lisbon, between Almada to the east and Trafaria to the west, intended to protect the rear of the other lines and navigation along the Tagus in case French forces from Andalusia appeared and tried to cut or cross the river, or bombard Lisbon. As these forces never appeared, the troops and artillery assigned to this fourth line ended up being distributed between the first two.