First, the War of Roussillon and Catalonia (1793-5) when, following the French Revolution, they landed troops in Catalonia to join up with Spanish forces and tried to attack France in the Pyrenees. It did not go well.
The second was the Peninsular War (1808-14) in which British troops joined the Portuguese and Spaniards to drive out the French who had occupied the Iberian Peninsula. The war turned the tide against Napoleon in Western Europe and made the reputation of the Duke of Wellington, who went on to become the victor of Waterloo.
The third commemoration is of a Portuguese auxiliary division that fought in one of Spain's civil wars in 1837.
And the fourth is the First World War, or Great War (1914-18). Portugal had been Britain's ally since 1377, but approached the conflict cautiously. It had been hoping to remain neutral, but there were clashes in Africa where German South-west Africa bordered Portuguese Angola.
Britain was at the time Portugal's most important overseas market, and when German U-boats tried to impose a blockade, Portugal seized German ships in its ports, so in 1916 Germany declared war. More than 12,000 Portuguese servicemen were killed in the conflict.
