AYATOLLAH ALI AL-SISTANI: As the supreme leader of the Shia majority in Iraq, the war catapulted the enigmatic and elderly Ayatollah Ali al-Sistani into the position of potentially the country's most important figure. His reputation as a moderate meant he was courted by the US. And despite his refusal to meet US officials directly, he has cooperated with coalition forces and the new Iraqi government. Little on Iraq's future could be agreed without the say-so of al-Sistani, who had a hand in the formulation of the election process and drafting of the Iraqi constitution. Shia ministers seek his advice. Yet, with his public appearances growing rarer, concerns have arisen over his health and the dangerous power vacuum that could emerge at his death. He now spends his days in an apartment in Najaf, the spiritual centre for Iraq's Shia Muslims.