Britain's newest nuclear submarine has been officially named HMS King George VI, the Ministry of Defence has confirmed.
The vessel will join its sister submarines in the Dreadnought class - Dreadnought, Valiant and Warspite - and makes history as the first naval vessel to bear that royal title.
This development marks 50 years of the Royal Navy's Continuous at Sea Deterrent (CASD), which has seen a Royal Navy ballistic missile submarine patrolling every day without interruption since April 1969.
Codenamed Operation Relentless thanks to it being the longest sustained military operation ever undertaken, it is designed to provide a deterrent against attack and keep the UK and its allies safe.
New defence secretary Penny Mordaunt said: "We pay tribute to those incredible crews, their supportive families, the Royal Navy and the thousands of industry experts who will continue to sustain this truly national endeavour for many years to come."
The Dreadnought class vessels are expected to enter service in the early 2030s.