Lt Col Chamberlain and 650 of his 1,000 troops currently based at the Contingency Operating Base (COB) Basra are now weeks away from leaving after Major General Andy Salmon stood down and handed over military command to the US Army last month.
And looking back, Lt Col Chamberlain, originally from Devizes but now based at 5 Rifles' base in Germany, is without doubt the British Army has left a significantly positive mark on Basra City and the surrounding province.
Standing in the COB next to one of the Warrior Armoured Fighting Vehicles he first entered Basra in as a company commander and Major in 2003, he said: "The Basra we entered was a depressed, Middle Eastern city. It was old, it was crumbling, it was dirty. The cars were old, there were no modern vehicles on the road, there weren't any satellite TV dishes. The electricity wasn't functioning, it was a very run down place. The population was very frightened, very subdued and not hugely happy.
"But now it's changed significantly. It's completely different. It's a vibrant place, the population is happy, the middle class has come back, so things are functioning in a way they weren't in 2003.
"It's changed immeasurably, electricity is on, cars are modern, there are satellite dishes on every building, some people have air conditioning, people don't rely on generators in the back yard, it's a proper, viable, functioning Middle Eastern city.
"Yes, there is still a need for new hospitals, there are still more schools required, there is still infrastructure needed. But that work is now happening, and that's the big difference; it wasn't happening in 2003.
"People were not getting what they needed, the middle class were leaving where they could. Now they're here. They're investing in their future," he said. "We have had two elections here, we've got democracy here, people have their say. Children are going to school on proper terms, in a proper education system."
British combat operations in Iraq will end on May 31 and nearly all of the UK's remaining 4,100 troops in the country will be withdrawn by July 31.