HMS Queen Elizabeth: Why is a UK aircraft carrier going on a world tour?

Britain is about to embark on a world tour - in the shape of the Royal Navy's aircraft carrier HMS Queen Elizabeth, accompanied by a fleet of warships.

The Royal Navy says it will be the most powerful UK naval deployment in a generation.

The government sees the fleet, named the Carrier Strike Group, as a potent symbol of "Global Britain" - and as proof of Boris Johnson's promise to restore the Royal Navy as Europe's foremost naval power and end what he called an "era of retreat".

The prime minister spent this morning on board HMS Queen Elizabeth in Portsmouth naval base, ahead of its maiden operational deployment.

But is this world tour more than a symbol of national virility or a flag-waving exercise?

And what's the point of sailing halfway across the world?

Over the next 28 weeks the Carrier Strike Group will cover 26,000 miles - further than the distance around the world at the equator.