During the 1980s, the Spanish Navy required an all-new, all-modern class of guided-missile frigate - this requirement to be eventually fulfilled by the Alvaro de Bazon-class(also known as the "F100" class). The series would number six total planned ships led by Alvaro de Bazan (F101) herself and include sisters Almirante Juan de Borbon (F102), Blaz de Lezo (F103), Mendez Nunez (F104) and Cristobal Colon (F105). However, two of the group, Roger de Lauria (F105) and Juan de Austria (F106), ended as cancelled ventures (Cristobal Colon took the F015 designator when she was added to the mix).
Origins of the Alvaro de Bazon-class was from a 1980s NATO program involving eight powers seeking to develop a "common" warship to be used between them. This was arranged under the "NFR-90" program which involved Spain as one of the contributors. However, in 1989, the program fell to naught, leaving the Spanish Navy to pursue an indigenous design and thus the F100-class was forged. The group was specifically designed as guided-missile frigates and given inherent capabilities to cover the sub-hunting, air space denial and operations support roles. Local Spanish industry would, of course, benefitted from the death of the NATO initiative.
The result was a technologically advanced warship suitable for countering modern threats and projecting Spanish naval authority in the region. A CODOG (COmbined Diesel Or Gas) propulsion scheme was selected which involved 2 x General Electric LM2500 marine gas turbines paired with 2 x Navantia Caterpillar 3600 marine diesels. Power was driven to 2 x shafts and speeds could reach 29 knots out to 4,500 nautical miles.
Internally, the warship would be staffed by up to 250 personnel including up to 48 officers. The primary system aboard would become the powerful "AEGIS" combat system promoted by Lockheed Martin (its AN/SPY-1D 3D multi-function radar series fit). Additionally, the warship was stocked with the Raytheon SPS-67(V)/4 surface-search radar, Raytheon DE116-LF active/passive sonar units and 2 x ARIES systems - the latter aiding in navigation. For disrupting inbound threats, 4 x FMC (Sippican Hycor) SRBOC Mk 36 flare/chaff launchers were added as was the SLQ-25A "Nixie" system to counter torpedo threats.
Armament became a generous mix of both conventional projectile and missile installations led by a single 5" /54 caliber Mk 45 Mod 2 series turreted deck gun fitted over the forecastle. 1 x 48-cell Mk 41 Vertical Launch System (VLS) provided the long-range missile capability which supported both the Standard SM-2MR Block IIIA missile series as well as the RIM-162 "Evolved Sea Sparrow" anti-aircraft missile. 8 x RMG-84 "Harpoon" anti-ship missiles gave the frigate a counter to surface threats and 4 x 324mm Mk 32 Mod 9 double-torpedo launchers (supporting 12 x Honeywell Mk 46 Mod 5 torpedoes) offered hope against enemy submarines. There was also provision given for a single 20mm FABA Meroka 2B Close-In Weapon System (CIWS).
Over the stern was added a helicopter landing pad to support a single Sikorsky SH-60B "Seahawk" (LAMPS III-equipped) navy helicopter. This could be used to broaden the warship's over-the-horizon capability and fulfill its anti-submarine requirement as the helicopters carried both sonar and missiles. There were also plans at some point to incorporate the Northrop Grumman "Fire Scout" helicopter UAV.
External measures were taken on the design to promote inherent stealth features such as the slab sides of the superstructure being well-integrated to the hull lines and many protrusions were purposely limited across the ship where possible. The aft superstructure was of a low-profile design which also included housing the smoke funnels, reducing the ship's radar signature and overall side profile. The main mast, however, was left exposed and of a pole-type arrangement.
With construction handled by Spanish shipbuilder NAVANTIA-IZAR, Alvaro de Bazan was officially launched in October of 2000 and formally commissioned in September of 2002 and remains in active service as of this writing (2017). Three similar vessels to the F100 standard were also ordered by the Royal Australian Navy.
Despite the class' categorization as frigates, some sources detail them as destroyers.