On a glorious morning on the Solent, the fifth of the six Type 45 destroyers built for the 21st Century Fleet made her debut in Portsmouth.

This is HMS Defender – and the only time you will see her flying the Blue Ensign in her home base of the next three decades.

Within a few hours of her inaugural entry to Portsmouth Naval Base, the destroyer hauled down that flag and hoisted the Royal Navy’s standard for the first time as she was formally handed over to the Senior Service.

As with all her predecessors there was a turn-out to welcome her – a good four dozen enthusiasts and families on Round Tower. Unlike some of her predecessors, it was a blazing hot day with not a cloud scarring the sky.

Defender left the BAE Systems yard at Scotstoun on the Clyde – where she’s been fitted out since her launch a short distance away at the same firm’s Govan works on Trafalgar Day in 2009 – on Saturday.

She was escorted some of the way down Glasgow’s great artery by the paddle steamer Waverley – the last of her type in the world and one of Defender’s affiliates (as is the city of Glasgow) – before reaching open waters and the 600-mile journey through the Irish Sea, Bristol Channel and around the southwestern tip of England, before heading up the Channel and into the Solent.

“Defender is a magnificent ship – a credit to BAE Systems and the British shipbuilding industry,”said her Commanding Officer Cdr Phil Nash.

“Sailing into Portsmouth for the first time was a very proud moment for me and my ship’s company.”

Defender now faces months of training before she’s ready to take her place in the line as one of the most advanced air defence destroyers in the world. The £1bn warship is due to be declared operational next year.

Of the four ships ahead of Defender in her class, Diamond, Daring and Dauntless are all on their maiden deployments, whilst HMS Dragon fired her main Sea Viper air defence missile system for the first time earlier this month.

The final vessel in the Type 45 programme, HMS Duncan, is in the last stages of completion at Scotstoun. She sails for the first time next month.