At the Nassau conference in December 1962, an agreement was reached between President J.F.Kennedy and Prime Minister Harold Mc Millan to allow the Royal Navy to purchase the Polaris submarine launched Ballistic Missile System, to compensate for the cancellation of the Skybolt airborne strategic system in 1961. At a stroke, the Royal Navy took over total responsibility for Britain's nuclear deterrent from the Royal Air Force.

The development of the Polaris programme placed an enormous strain on both the Royal Navy and the industrial economy, but much to the credit of both, the programme came in on time, and more importantly, within budget.

The original plan was for five boats, but the incoming Labour Government cancelled the fifth boat as a political gesture. This decision placed enormous pressures on the Polaris Submarine Force, as it was pledged to have a boat on patrol at all times. Using two crews (Port and Starboard) and tight refit schedules, the "Bombers" carried out their patrols for thirty years without any undue fuss until the introduction of the Vanguard Class Trident Submarines

When the final Polaris patrol was completed in 1996, the four boats had carried out a total of 229 two month patrols between them.