The scene is set for Isis’s last stand in Mosul

Remaining militants hole up in symbolic fight for city’s Grand Mosque, from which leader Abu Bakr al-Baghdadi declared the establishment of the so-called caliphate in 2014

Iraqis trapped inside the last tiny Isis-controlled pocket of Mosul have reported that militants have been shoring up defences outside the city’s Grand al-Nuri mosque, a symbolic move ahead of their final showdown with coalition forces.

In the last two days all roads leading to the beautiful medieval building on the west bank of the Tigris River have been sealed off, and families ordered behind the front lines to serve as human shields against approaching Iraqi troops, residents inside the city have said.

Isis swept across more than a third of Iraq from neighbouring Syria in a series of surprise attacks in the summer of 2014; its position as a powerful player in the region was assured when its fighters stormed Mosul, Iraq’s rich, cosmopolitan second city.

The city’s capture – home to 1.5 million people – was a surprise even to Isis. Shortly afterward its conquest, it was from al-Nuri mosque that Baghdadi, in his only public appearance to date, announced the creation of the so-called caliphate, imploring devout Muslims from across the world to join the extremists in their vision.

Iraq and its US-led coalition partners were never going to let the militants hold the city forever. But the fight has been more bloody, and taken longer, than expected. When Operation Inherent Resolve began in October 2016, Iraqi generals confidently predicted the battle would be finished by the end of the year. Eight months of gruelling street-by-street warfare, fending off suicide car bombs, snipers and boobytraps, the Iraqi authorities refuse to release casualty figures for fear of letting the enemy know their heavy losses.

Thousands of civilians are also dead – many after being accidently targeted in US-led coalition air strikes – and almost one million have been displaced by fighting to internally displaced persons camps around the region.

Up to 200,000 people are believed to still be trapped in the last three labyrinthine Old City neighbourhoods still under Isis control. Those who have managed to flee report that food and water are running out, and access to healthcare is almost non-existent.

In some cases, Isis has been sealing families inside their houses to prevent them escaping as Iraqi soldiers advance from the north, soldering doors and windows shut.

Isis’s black flag still flies from al-Nuri’s crooked minaret, but it’s unclear for how long. It’s very possible the mosque itself, which has not been structurally surveyed since 1970, will be destroyed in the coming fighting.

Even when Isis is vanquished, residents returning to the city may find nothing but rubble where their homes used to be. The group may morph into an insurgency movement rather than a land-holding force in the country, but the scars it has left on Mosul and its people will last for decades to come.