Relentless Mark 2 - 100 Up – the Strategic Submarine VICTORIOUS has completed what was the 100^th Strategic Patrol by a “V” Class Submarine.   Among the people on hand to welcome the “boat” home was the Prime Minister.  The Silent Service had performed the nuclear strategic deterrent for the last 45 years.   The (UK) POLARIS programme was announced in December 1962 following the Nassau Agreement between the USA and the UK with construction of the submarines beginning 1964, and the first patrol took place in June 1968.    In the 1970s it was determined that the re-entry vehicles which carried the warheads, were vulnerable to the Soviet anti-ballistic missile screen concentrated around Moscow and to ensure a credible and independent nuclear deterrent was maintained they were ungraded.   Thus the CHEVALINE was introduced but this only became public in 1980.   CHEVALINE allowed the POLARIS patrols to continue until May 1996, by which time the TRIDENT missiles were operational from the VANGUARD which had commissioned in August 1993 and went on patrol for the first time in December 1994.   More than 300 Strategic Patrols have safely and successfully been completed, in what was, and which continues to known as “Operation Relentless”.