The Ejército del Centro (Army of the Centre) was one of the four large corps, plus a reserve, that resulted from the re-organisation of the existing regiments and corps of the Spanish Army in the early months of Spain's War of Independence (1808-14), part of the Peninsular War (1807–1814).
The Junta Central published a political manifesto on 10 November 1808 (dated 28 October 1808), in which, among other declarations, it announced its intention of maintaining a force of 500,000 troops, together with 50,000 cavalry.
According to the manifesto, the Army of the Centre would be made up of the four divisions from Andalucia (under Castaños), together with those of Castile (under General Cuesta), Extremadura and those of Valencia and Murcia that had entered Madrid under Pedro González Llamas.
It was hoped that the British forces would join this Army in the event that they decided to advance up towards France.
The Ejército de Estremadura was never fully integrated into the Ejercito del Centro, although two of its divisions did participate at Burgos (10 November 1808) and some of its troops, together with troops from the Ejercito del Centro, fought at Somosierra (30 November 1808).