The Battle for the Tagus – Lippe's Masterful Defense and the Turning Point of the War (October 1762)

By October 1762, the Bourbon invasion of Portugal had reached a critical phase. With their initial successes in Beira, the Spanish and French forces under the Count of Aranda were now focused on breaking through the final Portuguese defenses and marching on Lisbon.

Count Wilhelm von Schaumburg-Lippe, aware of his numerical inferiority, abandoned the idea of defending the entire frontier and instead withdrew into the interior, forming a strategic defensive line along the River Tagus. This maneuver was essentially a forward defense of Lisbon, ensuring that the capital remained protected behind natural barriers.

Lippe’s Strategy – A War of Movement, Not Set-Piece Battles

Lippe’s primary objectives were:

1. Avoiding a direct battle with the superior enemy force – Instead of engaging in conventional combat, Lippe focused on controlling mountain passes and gorges, using small units to harass and attack enemy flanks.
2. Preventing the Franco-Spanish forces from crossing the River Tagus – If the enemy could cross the Tagus, they would reach Alentejo’s open plains, where their superior cavalry could march on Lisbon without opposition.

The Spanish Plan – Crossing the Tagus at Vila Velha

After capturing Almeida, Aranda moved swiftly to cross the Tagus at Vila Velha, a location historically used by Philip V of Spain to cross the river during the War of the Spanish Succession.

However, Lippe anticipated this move and acted first, securing:

• Abrantes, his main headquarters, a strategic position halfway between Lisbon and the Spanish border.
• Detachment placements:
  • Burgoyne was posted at Niza.
  • The Count of Santiago was positioned near Alvito to block the Spanish passage at Vila Velha.

When the Spanish army arrived at Vila Velha, they found that all strategic positions were already occupied and that the Portuguese had either taken or destroyed all boats—making a river crossing impossible.

This left the Bourbon forces with only two options:

1. Retreat into Spain and cross at Alcántara, which was strategically sound but dishonorable, as it implied they had been forced to withdraw before an inferior force.
2. Advance toward Lisbon via the mountains north of the city, a risky choice that played directly into Lippe’s hands.

As expected, Aranda opted for the second option, attempting a mountain march toward Lisbon.

The Bourbon Offensive Toward Abrantes

While Lippe’s Anglo-Portuguese forces fortified their positions in the mountains between the Tagus, Zêzere, and Codes rivers, the Bourbon army launched a desperate offensive aimed at breaking through toward Abrantes, Lippe’s headquarters.

The Battle of Vila Velha (October 3–5, 1762)

On October 3, the Spaniards seized the small castle of Vila Velha (on the north bank of the Tagus) and forced the defiles of St. Simon, pushing deep into Portuguese territory. A large Spanish force began pursuing the Count of Santiago’s detachment through the mountains, nearly cutting them off completely.

Realizing the danger, Lippe acted immediately, sending a reinforcement under Lord Loudoun. The combined Allied forces counterattacked and defeated the pursuing Spaniards at the River Alvito on October 3, allowing Santiago’s force to escape to Sobreira Formosa.

However, the Spanish advance had weakened their position at Vila Velha, leaving them vulnerable. On October 5, Anglo-Portuguese forces under Colonel Lee launched a decisive assault on Vila Velha, routing the Spanish garrison.

• A Spanish general was killed while trying to rally his troops.
• Several Spanish officers and soldiers were captured.
• Sixty artillery mules were seized, and enemy supplies and magazines were destroyed.

The Battle of Sabugal – A Simultaneous Allied Victory

On the same day (October 5, 1762), Portuguese forces under Townshend ambushed and defeated a French force escorting a supply convoy at Sabugal.

• A large quantity of supplies was captured, further strangling the Bourbon army’s logistics.
• This simultaneous defeat at Sabugal compounded the disaster at Vila Velha, ensuring that the Spanish offensive was completely stalled.

The Tide of War Turns – The Franco-Spanish Offensive Fails

The losses at Vila Velha and Sabugal were crippling for the Bourbon invasion:

• The offensive toward Abrantes had failed.
• The Spaniards could not cross the Tagus, preventing them from reaching Alentejo and the open plains leading to Lisbon.
• The Portuguese and British forces had proven highly effective, using strategic mobility, fortifications, and well-timed counterattacks to neutralize the numerically superior enemy.

Abrantes – The Key to Portugal

Abrantes had proved to be “the key of Portugal”, as its strategic location:

• Blocked the southern route to Lisbon.
• Served as a staging ground for Anglo-Portuguese counterattacks.
• Allowed Lippe to control enemy movements, forcing them into increasingly disadvantageous positions.

Conclusion – The War Had Turned Against Spain and France

The failure of the Bourbon army to cross the Tagus marked a turning point in the war. The Franco-Spanish offensive was over, and now, the Anglo-Portuguese forces would seize the initiative, launching counteroffensives that would force the invaders to retreat.

What had once seemed like a winning campaign for Spain and France had, by October 1762, transformed into a full-scale strategic disaster.