The morning we crossed the border from Kuwait into Iraq, dodging checkpoints and military police on a March afternoon in 2003, our first encounter was a geyser of burning oil arcing against a sky blackened by the smoke of burning wells.
As we were not embedded with the military, our plan was vague – head first to Basra, where British troops were still fighting to enter the city, and improvise from there in a car loaded with 200 litres of fuel in jerrycans and enough food and water for a fortnight.
Most of us had not covered a war like this before, with its high intensity airstrikes and vast columns of armour. Some, myself included, had demonstrated against it.
Now the invasion was in full swing and, even in those earliest days, the cracks it was triggering were beginning to appear, spidering through the fabric of Iraqi society.
A rumour spread of a mass grave that had been found by British troops, so we headed to a Sunni village in the largely Shia south, where bodies of several people were being exhumed, victims of the Saddam era.
As we left the site after the departing soldiers, the villagers appeared on a bank above the road with rocks. Despite the prewar talk of how the US-led invasion would be welcomed, there were places from the start where we were never welcome.
Basra was different. Walking in with a column of British paratroopers, at the invitation of an officer, on the day the city fell, people came out of their homes to greet the column, some offering sweetly sugared tea.
Unlike the village, Basra, which had suffered so much at the hands of Saddam, was happy at his impending fall. The lethal hostility towards the British from the myriad of Shia insurgent groups that would emerge there came later.
The war was moving fast.
The Americans were closing in quickly on Baghdad. Heading north we found the end of the main US supply route and, waved on by it, for a day followed an endless column of US armour, fuel tankers, and soldiers heading towards the Iraqi capital. The convoy was enveloped in its own cloud of dust which, even with the car windows closed, forced us to wear ski goggles and scarves around our faces.
We left the main supply route near Baghdad, where the US tanks we encountered were now vigilant and edgy, firing warning shots at approaching cars, our own included.
An hour or so later, the reason became clear. We were somewhere in the vast suburbs of Iraqi capital. Along the road were destroyed cars and burning low buildings. Bodies covered in carpets were dotted here and there – members of Republican Guard, Syrian and fedayeen fighters who had put up a last haphazard resistance to the entering US forces of the Third Infantry Division.
We crept in the fading evening light past tanks illuminated by nearby fires until we reached an overpass.
On the road sloping away, a US Bradley armoured car was pulled across in front of us. We could see soldiers deploying and covering us with weapons. Jumping from our cars, we waved frantically.
Escorted into the surreal opulence of the mausoleum of the Ba’ath party founder Michel Aflaq, where the US soldiers had set up their command centre, they told us of a supply column ambushed on that road and how they were a moment from targeting our vehicles.
We slept on a marble floor that night. The next morning we moved into the city centre, hopscotching carefully from tank to tank, asking them to radio ahead to warn of our approach. Finally, by the river, we crossed the lines separating the 3rd infantry from the marines, reaching the heart of Baghdad.
We had seen looting in the south as we came north, including a whole electrical generating unit from some kind of factory or power station being dragged along the motorway in a cloud of sparks, but in Baghdad it was on a staggering scale.
On our first morning in the city a hidden armoury in the basement of the ministry of planning, by the al-Jumhuriya Bridge and designed by the Italian architect Gio Ponti, was being emptied with wheelbarrows of weapons being pushed across the bridge or loaded into cars.
Inside, a couple of frightened US soldiers were trying to stop the theft of weapons that would later be used against American soldiers, but outside on the street it was a different story, one that would reflect the laissez-faire attitude of the Bush administration as it occupied Iraq.
A sanguine officer of the soldiers in the basement told us he had orders not to intervene, unconcerned until one of the looters fired an rocket-propelled grenade into a building as we were speaking.
Nowhere was immune to the looting.
In Baghdad’s medical city, a campus of hospital and training facilities, the looters seized fans from ceilings and the displays for vital surgical equipment. Medicines were taken – to be seriously ill or injured in those days meant the risk of dying.
One of the doctors took me to see a mechanic in a chaotic emergency department who had been shot as looters robbed his workshop. One bullet had struck him in the chest. The doctor tipped back the man’s chin to reveal how another had almost severed his windpipe.
A vacuum had descended on the city and the country. Everywhere you looked were discarded Iraqi uniforms, like castoff skins.
And into the void, new figures chasing power were beginning to muster.
Ahmad Chalabi, the slippery Iraqi exile founder of the Iraqi National Congress, who had help militate for the invasion with false information supplied by sources affiliated with his group, had set up in a luxury villa after entering Iraq with his grandiosely named Free Iraqi Forces.
In the Shia suburbs, a young firebrand preacher Moqtadr al-Sadr was also making his first moves in opposition to the INC.
Revenge killings, that would become increasingly sectarian, were just beginning. Slowly over the months to follow, other forces would coalesce – Sunni and Shia, insurgents and militias – that would lead to the horrors that to come under the US occupation.
• Peter Beaumont reported on the Iraq war from the invasion until 2007 for the Guardian and the Observer, winning the Orwell Prize for his coverage
