The destruction of the Mosul mosque where Isil’s leader declared his caliphate marks the group’s defeat, Prime Minister Haider al-Abadi said, as Unesco mourned the loss of one of Iraq’s most venerated sites.

The 12th century Grand Mosque of al-Nouri was captured three years ago by the jihadists, who blew it up with explosives on Wednesday night after Iraqi forces advanced to within 150 feet.

The mosque's famous leaning minaret, which earned the nickname of Iraq’s Tower of Pisa, had dominated skyline of Iraq’s second city for centuries and is pictured on the country’s 10,000 dinar banknote.