Defence Secretary John Healey was on hand to witness the steel cutting — Defence Secretary John Healey was on hand to witness the commissioning ceremony (Picture: MOD)

Mr Healey had a front row seat for the steel cutting — Mr Healey had a front-row seat for the event (Picture: MOD)

Mr Healey speaks at the ceremony (Picture: MOD)

King Charles reads the Commissioning Warrant at a formal ceremony to mark HMS Agamemnon entering operational service — King Charles reads the commissioning warrant at a formal ceremony to mark HMS Agamemnon entering operational service (Picture: PA)

Crowds welcome King Charles to Barrow-in-Furness (Picture: PA)

Navy

In pictures: Historic milestone as UK's newest submarine welcomed into Royal Navy fleet

The King and Defence Secretary welcomed the Royal Navy's newest nuclear submarine as HMS Agamemnon was commissioned.

In a rare change to naval tradition, King Charles read the commissioning warrant – declaring Agamemnon ready to take her place alongside the rest of the fleet at the ceremony at the BAE Systems shipyard in Barrow-in-Furness, Cumbria

HMS Agamemnon is the sixth of seven Astute-class fleet nuclear submarines built for the Royal Navy.

HMS Agamemnon is designed to protect the UK's strategic nuclear deterrent, aircraft carrier strike groups and critical undersea infrastructure.

The vessel can strike land targets up to 1,000 miles away, serve as a launchpad for raids by teams of Royal Marines Commandos and gather intelligence through state-of-the-art sensors.

She weighs 7,400 tonnes and is 97 metres long.

At the event, Lady Sarah Jane Sedwill, who has followed the progress of the boat and her 100 men and women since being named HMS Agamemnon's sponsor, praised all in Team Aggie for the efforts to bring the cutting-edge submarine to the cusp of frontline operations, providing "silent security to defend our nation, allies and interests for many decades to come".

HMS Agamemnon immersed for the first time