Naval branch of the armed forces of the United Kingdom.
Organized sea power was first used in England by Henry VIII built a fleet of fighting ships armed with large guns and created a naval administration. Under Elizabeth I the navy developed into Britain's major defense and became the means for extending the British Empire around the globe. The maritime forces were given the name Royal Navy by Charles II . In the 18th century it engaged in a long struggle with the French for maritime supremacy, and it later played a key role in Britain's stand against Napoleon . For the rest of the 19th century, it helped enforce what became known as the Pax Britannica, the long period of relative peace in Europe that depended on British maritime supremacy. It remained the world's most powerful navy until the mid-20th century, and it was active in protecting shipping from submarine attack in World Wars I and II. Today it maintains four fighting forces: conventional and nuclear-armed submarines, various surface vessels, naval aircraft, and the Royal Marines. Officers are trained at the Britannia Royal Naval College, Dartmouth, Devon. At the start of the 21st century some 42,000 personnel were in service.