He was born in 1950, so he’s 50 years old today. He took over after the Iraqi Transitional Government in 2006. He got into politics as a Shia dissidant against Saddam in the 70’s, and fled into exile in the 80’s to escape a death sentence. From abroad, he collaborated with people in Iran and Syria to overthrow Saddam. He got a masters in Arabic literature from Baghdad University. His grandfather was poet and cleric serving under King Faisal.
When he was abroad he lived in Iran until 1990 (in Tehran), then moved to Damascus, Syria. There he got in close with Hezbollah and Iran, since these countries were also interested in toppling Sadman. The US begin heavily funding some of the antiSaddam groups he was involved in.
After the US handed over power to Iraq in the 2005 elections, the United Iraqi Alliance won the most seats and nominated Ibrahim al-Jaafari to be prime minister, but this guy soon gets ousted (in part thanks to the US, who finally decided he was too close to Iran for their taste). al-Maliki steps in at this point. So al-Maliki is basically chosen not because simply for his qualities as leader, but specifically because he appears to keep up the antagonism with Iran.