The latest of the Royal Navy's new Type 45 air defence destroyers has been formally commissioned into the fleet today.
HMS Diamond is one of six multi-role vessels being built to provide air defence using the Sea Viper missile system.
She can embark 60 troops and their equipment, supported by a modern medical facility that can deliver a surgical capability. She could also carry up to 700 people to support a civilian evacuation.
The Defence Secretary, Dr Liam Fox, said:
"The Type 45 programme is an example of how we are investing in capabilities for the future. This ceremony marks another step in the delivery of six of the most powerful air defence destroyers ever built for the Royal Navy. These new ships will provide the UK with a world class military capability that will form a key part of the Future Force 2020."
Hundreds of guests including families of the 190-strong ship's company attended the ceremony at Portsmouth Naval Base which was conducted by the Reverend Scott Brown, Chaplain of the Fleet.
During the ceremony the ship's sponsor, Lady Johns, who launched the ship at BAE Systems' Govan shipyard on the River Clyde in November 2007, inspected the members of the ship's company on parade.
HMS Diamond's Commanding Officer, Commander Ian Clarke, read out a Commissioning Warrant and the ceremony was rounded off in traditional Royal Navy fashion with the cutting of a commissioning cake.
Performing the honour was the Commanding Officer's wife Joanne and Engineering Technician Ross Hindmarch, who, at 17, is the youngest member of the ship's company.
Commander Clarke said:
"This is a proud moment for all on board HMS Diamond. As she nears the end of her trials phase, this ceremony marks our transition to front line service.
"Thereafter, the emphasis will be on combat readiness in preparation for our first deployment next year. I'm thrilled that so many families, friends and affiliates, some from overseas, were part of our momentous day."
All the Type 45s will be based in Portsmouth. The first, HMS Daring, was commissioned in July 2009, followed by HMS Dauntless in June last year.
The fourth, Dragon, is due to arrive in Portsmouth for the first time in September. All six are scheduled to be in service by the middle of the decade.