Baghdad is Baghdad, there is no former name for the city, nor Persepolis or Babylon.
Iraq "had" (and still has) a capital of Baghdad Province. That capital "was" (and still is) Baghdad City. Or were you trying to ask "What country is Baghdad the capital of"? In which case the answer would be; The capital city of Iraq is Baghdad.
From Baghdad to Peace Country was created in 2003.
Baghdad Was Built BY Abassid Caliphate Abu Jafar Al-Mansur in 762 A.D
in 762/144
The Liberace of Baghdad happened in 2005.
Blackwater Baghdad shootings happened in 2007.
Mihăileşti explosion happened in 2004.
Delft Explosion happened in 1654.
Oaks explosion happened in 1866.
Kingsland Explosion happened in 1917.
Clarkston explosion happened in 1971.
Vergarola explosion happened in 1946.
Bidganeh explosion happened in 2011.
Oppau explosion happened in 1921.
Explosion of the RFA Bedenham happened in 1951.
Silvertown explosion happened on 1917-01-19.