On 17 March 2003, US President George W Bush gave Saddam Hussein and his sons 48 hours to leave Iraq or face war. Two days later the first air strikes on Baghdad began. <b>Warning this gallery contains some disturbing images.</B>

Refugees stream from Basra in southern Iraq. The city was encircled by British forces on 22 March 2003 and humanitarian concerns for Basra residents grew when the city's utilities – including the water supply - were cut off.

As US-led coalition troops pushed northwards, extremely fierce sand storms blew up on 25 March, slowing their advance. However, targeted air strikes on Baghdad continued, and violent bombing to the south of the city brought the frontline ever closer.

After weeks of fighting, US troops pushed their way into central Baghdad. In a symbolic move, on 9 April, US soldiers pulled down a statue of Saddam Hussein in the city centre, cheered on by a crowd of Iraqis. The Iraqi leader himself went into hiding.

On 1 May 2003, President Bush made a speech on the deck of the aircraft carrier USS Abraham Lincoln, decorated with a banner reading Mission Accomplished, in which he declared that major combat operations in Iraq had ended.

In December 2003, the former Iraqi president, Saddam Hussein, was tracked down to a hole in the ground near his hometown of Tikrit and captured by US forces. Announcing the news on 14 December, Paul Bremer, the-then US governor of Iraq said: "We got him."

Iraq's oil pipelines frequently became targets for saboteurs. Here British soldiers secure an area near the burning oil export pipeline from the southern city of Basra, in March 2004.

Throughout 2004 tensions between Iraq's Sunni and Shia communities worsened, with suicide bombings, like this one at an Iraqi army recruitment centre in Baghdad, becoming more frequent.

On 31 March 2004, insurgents ambushed and lynched four US military contractors in Falluja. In April, US forces attacked the city. They failed to seize control in that assault, but in a second attack in November they succeeded, killing 1,000 militants.

In May 2004 photographic evidence emerged of Iraqi detainees being abused by US military guards in Baghdad's Abu Ghraib prison. The episode profoundly tarnished the reputation of the US military. Eleven soldiers were eventually jailed.

Innocent civilians getting caught up in the violence also worsened relations between Iraqi people and the coalition troops. Here, a child screams after US troops opened fire on her parents' car.

Throughout the US-led invasion there were fears that Iraqi forces could use chemical or biological weapons. But in October 2004 the chief US weapons inspector concluded that Iraq had no stockpiles of biological, chemical or nuclear weapons.

On 19 September 2005, angry crowds in Basra attacked a British tank with petrol bombs and rocks after Iraqi authorities said they had detained two British undercover soldiers in the southern city for firing on police. Two Iraqis died in the violence.

On 15 December 2005, Iraqis voted for the first, full-term government and parliament since the US-led invasion. After months of deadlock, Shia compromise candidate Nouri al-Maliki forms a new government in April 2006.

In February 2006, a bomb attack nearly destroyed the Golden Mosque in Samarra, a revered Shia shrine. The attack unleashed a wave of sectarian violence in which hundreds of people were killed.

On October 19 2005, Saddam Hussein was put on trial for crimes against humanity over the 1982 killings of 140 men in the town of Dujail. On 5 November 2006 he was sentenced to death by hanging and his execution took place on 30 December.

In 2006, the US military began to reach out to Sunni tribesmen, who had previously been sympathetic to al-Qaeda in Iraq. The formation of Sunni Awakening Councils, funded and armed by the US, came to be seen as a turning point in the war.

In September 2007 British forces withdrew from the city of Basra to a base at Basra airport. They ended all combat operations in southern Iraq and hand over to the US military in March 2009.