The Battle of Alcántara (14 May 1809) saw an Imperial French division led by Marshal Claude Perrin Victor attack a Portuguese detachment under Colonel William Mayne.

Alcántara, Spain is situated on the Tagus river near the Portuguese border, 285 kilometres (177 mi) west-southwest of Madrid.

Pierre Belon Lapisse's division lurked near Ciudad Rodrigo while Victor's I Corps operated in the Tagus valley.

A weak force under Robert Wilson watched Lapisse while Alexander Randoll Mackenzie's Anglo-Portuguese corps kept an eye on Victor.

When Sir Arthur Wellesley's Anglo-Portuguese army advanced to attack Soult's corps, the detachment under Mayne occupied Alcántara.

[1] This episode came to an end on 21 August 1808 when the invaders were defeated by Sir Arthur Wellesley's British army at the Battle of Vimeiro.

[3] Sir John Moore and his British army departed from Portugal in October 1808, intending to help the Spanish nation throw off Emperor Napoleon's yoke.

Meanwhile, Lapisse was directed to move from Salamanca to seize Ciudad Rodrigo and Almeida, Portugal as soon as Soult's II Corps got to Porto.

The emperor expected that Soult, Lapisse, and Victor would readily be able to send messengers to each other, and easily coordinate their operations.

Soult's cavalry crushed a Spanish brigade at La Trepa on 6 March and the II Corps entered Portugal on the 9th.

[10] But despite being established in Porto, Soult found his communications cut by regular and irregular Portuguese forces under General Francisco Silveira and he had no idea of the whereabouts of Lapisse.

[11] Meanwhile, Marshal Victor won a resounding victory over General Gregorio García de la Cuesta's Spanish army at the Battle of Medellín on 28 March 1809.

Though he went on to occupy Mérida, Victor complained in dispatches to King Joseph Bonaparte that he lacked the strength to invade Portugal.

[12] Moore's departure with the main British forces left Portugal defended by a scanty garrison under Sir John Cradock.

[14] Facing widely separated French opponents, Wellesley decided to attack Soult first while observing Victor.

When the French soldiers managed to brave the defensive fire and gain a foothold on the north bank, Mayne ordered a retreat to the Salvaterra Pass.

Wellesley reassured his subordinate that he had nothing to worry about, that Victor could not spare enough soldiers to present a real threat to his position behind the Zêzere River.

The raid failed to dislodge two battalions of Jean Francois Leval's German division from a fortified convent.