Britain's latest nuclear-powered submarine has been unveiled.

HMS Artful, a 7,400-tonne, 97-metre-long attack submarine, was officially named in front of thousands of guests in an event to mark its completion at the Devonshire Dock Hall in Barrow-in-Furness, Cumbria.

Artful, the third of seven Astute-class submarines, has now moved a step closer to joining her sister vessels HMS Astute and HMS Ambush.

The other submarines in the class in various stages of design or build are Audacious, Anson, Agamemnon and Ajax.

The Astute class of vessels, while nuclear powered but not nuclear armed, have greater conventional missile firepower, state-of-the-art communications equipment and advanced stealth technology, making them quiet and harder to detect, according to the Ministry of Defence.

Royal Navy submarines patrol the seas for months at a time, providing a key part of the UK's armed defence.

Built by BAE Systems, the Barrow yard has been working on the Astute programme since 2001.

Friday's ceremony was performed by Amanda Lady Zambellas, wife of the Royal Navy's First Sea Lord, Admiral Sir George Zambellas, inside BAE Systems' giant submarine construction facility.

John Hudson, managing director of BAE Systems Maritime - Submarines, said: "The design and build of a nuclear-powered submarine is as challenging as it is complex, so today represents a significant milestone in Artful's programme.

"It requires real skill and innovation to deliver submarines as sophisticated as Artful and this would not have been possible without the valued contribution of our employees and the collaborative efforts of the whole submarine enterprise.

Sir George Zambellas said: "Today's naming ceremony in Barrow for Artful adds another capable nuclear submarine to the gathering momentum in the Astute class.

"Ahead of her, HMS Astute and HMS Ambush are already being pressed hard towards operational use, contributing to the wider renaissance in the UK's naval equipment programme and adding to the Royal Navy's operational authority."

Artful will remain in the Barrow yard to complete a series of commissioning activities, before being launched in early 2014 for further tests and commissioning.