The Spanish Army is one of oldest active armies in the world and a branch of the Spanish Armed Forces, in charge of land operations.The Spanish Army (Ejercito de Tierra) has existed continuously since the reign of Ferdinand and Isabella. The oldest and largest of the three services, its mission was the defense of peninsular Spain, the Balearic Islands (Spanish, Islas Baleares), the Canary Islands (Spanish, Islas Canarias), Melilla, Ceuta, and the Spanish islands and rocks off the northern coast of Africa. The army is completing a major reorganization. It had previously been organized into nine regional operational commands. These were reduced to six commands in conjunction with a revised deployment of forces: Central Command, Southern Command, Levante Command, Eastern Pyrenees Command, Northwestern Command, and Western Pyrenees Command. In addition there were the two military zones of the Canary Islands and the Balearic Islands. Ceuta and Melilla fell within the Southern Command. At the head of each regional and zonal command was an officer of two-star rank. Although his authority had been reduced, the regional commander, who held the title of captain general, was still among the most senior officers of the army.

Under its earlier organization, the army was grouped into two basic categories: the Immediate Intervention Forces and the Territorial Operational Defence Forces. In theory, the former, consisting of three divisions and ten brigades, had the missions of defending the Pyrenean and the Gibraltar frontiers and of fulfilling Spain's security commitments abroad. The latter force, consisting of two mountain divisions and fourteen brigades, had the missions of maintaining security in the regional commands and of reinforcing the Civil Guard and the police against subversion and terrorism. In reality, most of the Immediate Intervention Forces were not positioned to carry out their ostensible mission of protecting the nation's borders. Many units were stationed near major cities--as a matter of convenience for officers who held part-time jobs--from which they also could be called upon to curb disturbances or unrest.