The Spanish Army (Spanish: Ejército de Tierra; lit, "land/ground army") is the terrestrial army of the Spanish Armed Forces responsible for land-based military operations. It is one of the oldest active armies - dating back to the late 15th century.
The Spanish army has existed continuously since the reign of King Ferdinand and Queen Isabella (late 15th century). The oldest and largest of the three services, its mission was the defense of peninsular Spain, the Balearic Islands, the Canary Islands, Melilla, Ceuta and the Spanish islands and rocks off the northern coast of Africa.
During the 16th century, Habsburg Spain saw a steady growth in its military power. The Italian Wars (1494–1559) resulted in an ultimate Spanish victory and hegemony in northern Italy by expelling the French. During the war, the Spanish army transformed its organization and tactics, evolving from a primarily pike and halberd wielding force into the first pike and shot formation of arquebusiers and pikemen, known as the colunella. During the 16th century this formation evolved into the tercio infantry formation. The new formation and battle tactics were developed because of Spain's inability to field sufficient cavalry forces to face the heavy French cavalry.