Muqtada al-Sadr and his armed group, the al-Mahdi army, have been America's most intractable opponents in Iraq, the only major Shia party to make the demand for US troops to withdraw.
For five years, they have controlled large sections of the country, they have also defied attempts to marginalise them politically, and have fought pitched battles with US Marines. Despite all this, al-Sadr's al-Mahdi army has only grown in size and influence.
The movement fought hard against Saddam's regime and no neighbourhood in Baghdad faced more brutal repression than Sadr City. Today, the same movement and the same neighbourhood are at the centre of resistance to the US occupation.
The US has tried, unsuccessfully, to destroy the Sadrists several times since the invasion in 2003. This spring, the Iraqi and US military launched surprise attacks against Sadrist strongholds in Basra and Baghdad. After a few weeks of stiff resistance ceasefires were negotiated and the al-Mahdi army melted away from the street.
Iraqi soldiers have set up bases inside neighbourhoods that they could not enter one year ago, and a wave of optimistic stories are coming out of Baghdad and Washington.
Did the surge work? Has the al-Mahdi army finally been defeated, and is this the end of the armed Shia resistance to the occupation?
Filmmakers Rick Rowley and David Enders returned to the al-Mahdi army stronghold in Baghdad's Sadr City to look for answers.