The Spanish Navy, or Armada, is one of the oldest naval forces in the world. It has a long and glorious history beginning in the thirteenth century, when the Spanish monarchs used their naval power to suppress the pirates in the Mediterranean, conduct warfare against enemies and expand their territories. Apart from protecting and expanding Spanish territorial sovereignty, the Spanish Navy contributed enormously to the geographical knowledge of the world, by opening shipping routes across the Atlantic and the Pacific oceans. It assisted in commercial activities by transporting gold and silver from the Spanish colonies in America. The Spanish navy also contributed to the technological development of such marine vessels as the galleon and the submarine.

Information from the late 1980s shows that the Spanish Navy holds second position in Europe in terms of total tonnage. It comes only after the British Navy, which has an equally formidable history. The Spanish Navy consists of more than 45,000 personnel, both male and female. The Spanish Navy is divided into four zones: the Cantabrian Maritime Zone, with its headquarters at El Ferrol on the Atlantic coast; the Straits Maritime Zone, with its headquarters at San Fernando near Cadiz; the Mediterranean Maritime Zone, with its headquarters at Cartagena; and the Canary Islands Maritime Zone, with its headquarters at Las Palmas de Gran Canaria. The Spanish Chief of Naval Staff has his headquarters in Madrid.

The personnel in the Spanish Navy can be divided into administrative units and operational units. Depending on the type of function they perform, the operational units of the Spanish Navy can be classified into combat forces, protective forces and auxiliary forces. The combat forces carry out offensive and defensive maneuvers against perceived enemies. Their principal vessels include two carrier groups, naval aircraft, transports and landing vessels, submarines, and missile-armed fast attack craft. The protective forces, as their name indicates, protect naval communications and installations. They also watch over the ports and other maritime terminals. Their principal vessels are destroyers, frigates, corvettes and minesweepers.

The auxiliary forces of the Spanish Navy carry provisions and troops to ships already stationed at sea. They carry out scientific research, and help to maintain naval vessels. They also function as a Spanish coast guard. In addition to supply ships and tankers, their fleet consists of supply ships, tankers, destroyers and patrol craft. The second largest vessel of the Spanish Navy is the aircraft carrier, Principe de Asturias. It has been in service since the year 1988. The vessel was built in Spain with the aid of American designers. The ship was designed with a "ski-jump" takeoff deck. It can accommodate six to eight Harrier vertical (or short) takeoff and landing (V/STOL) aircraft and as many as sixteen helicopters designed for antisubmarine warfare and support of marine landings.