Iraqi forces defeated the extremist group in the last of its urban strongholds last year, recapturing Mosul in a fierce battle that saw the al-Nuri mosque destroyed. Dignitaries from the E.U. and the U.N. attended the ceremony in the mosque's courtyard, where Abdulateef al-Humayim, head of Iraq's Sunni endowments, led the proceedings on Sunday.
The UAE donated $50.4 million to rebuild the mosque. Construction is expected to take five years.