All of Isis’s previous victories paled in comparison to the capture Mosul, one of the biggest defeats in the history of Iraq: the fall of its second city, the rout of 50,000 soldiers and policemen, and the capture of hundreds of tonnes of weapons, equipment and armoured vehicles.

And it was here in Mosul where Isis would attempt its most ambitious plan yet, the basis for its claims to legitimacy: to transform from an insurgency into a state.

A week in, Isis issued its first manifesto: the Madina [City] Document. In archaic language laden with millenarian references, Isis congratulated the people of Mosul for “these divine victories” and staked out its central promise:

Oh people, you have tried all the secular regimes, from the monarchy to the republic to Safavid [Shia] government. You have tried it and been burned by its fires. And here we are now in the reign of the Islamic State and the region of our imam Abu Bakr. And you shall see by the will of Allah the vast difference between a secular government, that oppresses and confiscates the will and energies of its people and erases their dignity, and our rule, which takes the divine word as a path. 

The document banned cigarettes and insisted women should stay home, but in the streets people continued to smoke, hookah cafes flourished, women went unveiled, and many of the families that had fled Mosul returned.

The Madina Document was just the first step, however. The so-called Islamic State did not spring up in a single day. It arrived gradually, over roughly two months, via a series of actions and edicts – each new step affecting a different segment of society, raising the heat each time. 

In many ways, Isis’s project resembled other attempts through history to build a utopian state, from the Bolsheviks to the Taliban – a road map of authoritarian rule. First, promote a mythical founding ideology. Next, use it to purge society of undesirables. Use the utmost brutality so as to thwart any resistance; maintain a ruthless intelligence network to induce the population to denounce itself.

But totalitarian regimes can’t survive on millennial ideology and mass terror alone. They need a functioning bureaucracy and competent administrators.

Isis began by conducting an extensive census in Mosul. Army and police personnel, doctors, nurses, engineers and teachers were all registered, along with their families. Every shop, factory and commercial property was listed according to the religion and sect of its owners. “They came to us and opened the big land ledgers,” a clerk in the agriculture department told me. “They wanted to know which lands were owned by Christians, Sunnis or Shia. We told them these documents go back to Ottoman times, and we only have the names of the owners – there is no way to find their religion, let alone their sect.”

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