The Peninsular War, known in Portugal as the French invasions and in Spain as the Spanish Independence War took place between 1807 and 1814, in the Iberian Peninsula. This war was part of a much broader conflict that affected all of Europe - The Napoleonic Wars.
The French invasions were one of the greatest military offensives ever held in Portuguese territory, which left deep scars in the places and the people of that time; nonetheless the Anglo-Portuguese resistance marked the beginning of the retreat of Napoleon Bonaparte conquests.
In the early nineteenth century, Napoleon was "lord" of almost all of Europe. Invincible on land decreed, in 1806, the "Continental System" demanding the closing of all European ports to British ships so as to economically strangle the opponent.
In this scenario of hostility between two great powers - France and England - vying with each other the hegemony of Europe, Portugal was faced with a dilemma: obey Napoleon and antagonize its old ally, or remain loyal to the British by declaring war on France. The position of neutrality assumed did not pleased Napoleon who, in September 1807, issued new order for the closure of the Portuguese ports. However, only on November 5th, learning that the Napoleonic troops had entered Spain, Portugal solves to prevent the movement of British ships, underway since the first French invasion.
In November 1807, Jean-Andoche Junot arrived in Lisbon in time to see from the Tagus, the royal family and the Portuguese court, leaving towards Brazil. In August 1808, the Anglo-Portuguese army defeated the French troops in the battles of Vimeiro and Roliça - this was the first of three French failures to conquer Portugal.
In 1809, General Soult led the second French invasion in an offensive from the north of the country that culminated in the sad episode of the fall of the Ponte das Barcas in Porto (March). Pressured by the Anglo-Portuguese army, the French withdrew to Spain (May).
In July 1810, Marshal Andre Massena renews the French offensive to Portugal, in command of the third invasion. After suffering a defeat at the Battle of Buçaco (September), he reorganized his troops and proceeded to march to Lisbon. Wellesley (the future Duke of Wellington) anticipated the attacker and the allied army pushed back to the defenses of the capital - The Lines of Torres Vedras. Faced with this insurmountable obstacle, Massena began its withdrawal from the country in March 1811.
This defeat was the harbinger of the end of Napoleon's dream of dominating all of Europe.
The Lines of Torres Vedras are a defensive military system erected north of Lisbon, between 1809 and 1810. In the deepest secrecy, the future Duke of Wellington, accompanied by his chief engineer, Colonel Fletcher, generals of the British and Portuguese armies and the maps of Major Neves Costa, devised a defense strategy which consisted in fortifying points at the hills tops, controlling the roads to the capital of the Kingdom and enhancing natural terrain obstacles. The defense works were distributed along three lines that stretched between the Atlantic Ocean and the Tagus River.
The First Line with 46km linking the river Tagus in Alhandra, to Sizandro mouth in Torres Vedras, passing Arruda and Sobral. The large advanced military works of Alqueidão and St. Vincent had a function to block the main access routes to the Portuguese capital.
The Second Line, situated 13km south of the former, with 40km, going from Vialonga until Ribamar, passing Bucelas and Mafra.
The Third Line, with a perimeter of 3km, protected the embarkation of British troops, in case of withdrawal, it followed the route of Paço de Arcos to Junqueira Torres (Towers).
When completed, the Lines of Torres Vedras stretched for more than 85 km, with 152 counted military works, armed with 600 pieces of artillery, and defended by about 140 000 men. The cost of its construction will have been around 100 000 pounds, making it not only the most effective defense system, but also the less expensive one of all times in military history.
The Forts of Sobral, by their position on the ground, took a leading tactical importance in the plans of Arthur Wellesley: if the enemy exceeded the stronghold Alqueidão would have at its disposal the interior routes of the Lisbon Peninsula and the running of the Tagus River, compromising all defensive units.
At rear of Alqueidão, the British commander fixed his headquarters and made the village of Sobral an outpost later abandoned with the arrival of the French troops, as it is situated north of the overly defensive line. By observing the position of Alqueidão, Massena refused to make any attack on a formidable slope and decided to withdraw from the lines on November 15th, 1810.
In "Memories of the 3rd French Invasion", Colonel Noël described the feeling of French troops in front of the Lines of Torres Vedras, which all contributed to the failure of the Napoleonic army:
"We thought of ourselves as victorious, we thought we had reached the end of a glorious campaign and achieve our winter barracks in the capital of Portugal, but we have to pass a devastated country (...) next to these terrible lines, on whose soundness cannot delude ourselves (...). The general-in-chief decides to move the army back (...)."
The situation of the French army stationed at the gates of Lisbon deteriorated due to lack of supplies and poor weather conditions. On November 15th, under cover of fog, Massena began to withdraw his troops without Wellington noticing; this slowed the reaction by the Anglo-Portuguese army. On March 4th all resources were exhausted, so the French continued their retreat towards the Mondego valley.
Already with the French troops arriving at the Spanish border, Wellington defeated Massena on May 13th, 1811, at the Battle of Fuentes de Onoro, thus preventing the enemy from crossing the Portuguese border.
The retreat of Napoleon's army into Spain continued until the Anglo-Hispano-Portuguese troops reached France in late 1813. Pressed militarily throughout Europe with the invasion of France itself, Napoleon was forced to capitulate; the Bourbons regained the French throne on May 30th, 1814, with the signing of the Treaty of Paris.
Less than a year later, Napoleon returned to power, but was defeated at the Battle of Waterloo in June 1815, by the armies of the Seventh Coalition, which included a British force led by the Duke of Wellington and a Prussian force commanded by Gebhard Leberecht von Blücher.
This confrontation marked the end of the Hundred Days and was Napoleon's last battle. His defeat ended his rule as Emperor. Napoleon spent the last six years of his life confined by the British on the island of St. Helena and Europe started a new cycle in History.