The cells smelt of stale sweat, prison grime and something that could have been the death of hope. On the crowded floors thin, shaven-headed men in orange suits lay on their sides crammed together, the chest of each pressed into the back of the next, so that no other phrase than “tinned sardines” could better describe the wretchedness of their situation.

These are the vanquished of Islamic State: 5,000 men in a single improvised prison, citizens of Britain, France, Belgium and the United States among them. All had heeded the call of Abu Bakr al-Baghdadi and flocked to join the caliphate in Syria and Iraq before it was finally crushed this year.

Another 7,000 men languish in similar conditions near by, in six other prisons