What was the name of Britain’s first nuclear-powered submarine, commissioned in 1963?

HMS Dreadnought was Britain’s first nuclear-powered submarine, commissioned in 1963.

The Royal Navy built Dreadnought with major American assistance, including an S5W nuclear reactor supplied through the 1958 U.S.–UK Mutual Defence Agreement. The submarine was laid down in 1959, launched in 1960, and commissioned on 17 April 1963. Its nuclear propulsion gave it much greater endurance and underwater speed than Britain’s diesel-electric submarines.

Dreadnought was an attack submarine rather than a ballistic-missile submarine. Britain’s later Resolution class carried the Polaris missile, while Dreadnought served as a hunter-killer boat. It also became the first British submarine to pass beneath the North Pole, doing so in 1971 with HMS Valiant.

The name is sometimes associated with the famous battleship HMS Dreadnought of 1906. They were separate vessels, but both represented major technological changes in British naval history.