"Hunter killer" submarines (designated SSNs by the RN) are designed to pursue and attack enemy submarines and surface ships using torpedoes. They are also able to carry "cruise" missiles for use against shore-based targets.
1999 -- 16-20? cruise missiles fired by a British submarine during Nato's air campaign against Yugoslavia. HMS Splendid, based in the Adriatic, was the first British submarine to fire the US-made Tomahawk missiles in anger, becoming the first British nuclear submarine to fire on an enemy since H.M.S Conqueror in 1982 (Falklands).... The Royal Navy later used cruise in the 2001 Afghanistan War and Operation Telic, the British contribution to the 2003 Iraq War.
It is planned that all Royal Navy submarines will be Tomahawk capable by 2008, including the future Astute class attack submarine.