As Britain hands over security control of the last province in southern Iraq, Panorama marks the end of nearly five years of occupation.
Jane Corbin who was with British troops when they took over Basra Palace in March 2003 presents the second of a two-part investigation.
Panorama: Basra - The Legacy, Monday 17 December 8.30pm BBC One
What sort of place will the British troops be leaving behind?
Panorama investigates the dark heart of Basra today, once Iraq's most cosmopolitan city.
A city where women are murdered for wearing bright clothes.
Where being the wrong kind of Muslim can lead to torture, or murder.
Where powerful militias and criminal gangs operate freely.
And where corruption is rife.
All of this has happened on the British watch.
Jane Corbin meets Basra's new police chief
The film follows the trail to Syria where thousands of people from Basra have fled into exile and where people speak out about their experiences.
Jane Corbin also meets the new Iraqi police chief of Basra, Major General Abdul-Jalil Khalaf.
He is determined to restore law and order to a once-great city, despite almost daily assassination attempts.
Panorama: Basra - The Legacy, Monday 17 December 8.30pm BBC One.