Royal Navy

The Royal Navy (RN) is the United Kingdom's principal naval warfare force. Naval forces were first used by Alfred the Great in the 9th century, and from the early 14th century England's navy was engaged in maritime warfare. The modern Royal Navy traces its origins to the early 16th century, it is the oldest of the armed services and is known as the Senior Service.

During the 17th century the Royal Navy vied with the French Navy for world supremacy, and from the late 17th century until the mid- 1940s it was the most powerful navy in the world, being surpassed by the US Navy after World War II. The Royal Navy played a key part in establishing the British Empire as the dominant world power during the 17th, 18th, 19th and first part of the 20th centuries. Due to this historical prominence, it is usual – even among non-Britons – to refer to it as "The Royal Navy" without qualification.

Following victory in the First World War, the Royal Navy was significantly reduced in size, although at the onset of the Second World War it was still the largest in the world. By the end of the Second World War, however, the United States Navy had emerged as the world's largest. During the course of the Cold War, the Royal Navy transformed into a primarily anti-submarine force, hunting for Soviet submarines, mostly active in the GIUK gap. Following the collapse of the Soviet Union, its focus has returned to expeditionary operations around the world.