Failure to seize Buenos Aires.

In 1807, during the Napoleonic Wars with France and its ally (at that time) Spain, the 1/87th Regiment was part of the Expeditionary Force, commanded by Lieutenant General Whitelock, that attempted to capture Buenos Aires. The British aim was to control the region of the River Plate, an area dominating the South Atlantic where the trade winds were important for passage around Southern Africa. Buenos Aires was the capital of the Spanish Viceroyalty of the Río de la Plata.

After a very difficult landing and a long approach march to the city, 5,000 British troops mustered for the attack at dawn on 5 July 1807. At 0630 hours the attacking columns entered the city and advanced about one mile before meeting any resistance; then two enemy guns to their front began firing grape shot causing the ranks of the advancing 1/87th to waver momentarily until they moved off that route.

As the other attacking columns had encountered strong opposition from the Spanish, the attempt to capture the town had by nightfall failed. Only the 1/87th's Brigade had had any success and it was still fighting strongly. Owing to the stalemate and the heavy casualties the British Commander arranged a truce on the following day and agreed to withdraw. It was a defeat.

Although the troops had fought magnificently in the unfamiliar street battles, over 1,000 officers and 320 men were wounded. Whitelock returned to England where he was later court martialled and discharged. The victorious colonial militia would soon fight for their independence and in 1816 Argentina declared freedom from Spanish colonial rule; it was the beginning of the end of Spanish rule in South America.