Britain has begun withdrawing about 550 troops, from a base at Basra Palace, to the last remaining British base near the city's airport.
Around 500 of Britain's 5,500 soldiers in Iraq are stationed at the Basra palace.
The palace was built for Saddam Hussein and is located in the centre of Iraq's second city.
The withdrawal is a step towards handing over the province to Iraqi control, and paving the way for an eventual withdrawal of British forces from Iraq.
