In late April 2012, frightened inhabitants of Timbuktu reported a ghostly figure criss-crossing the town on a white horse. He was ‘dressed all in white, with a length of cotton bound round his face in the Tuareg style’. He warned local lovers to cease their public canoodling and head home. This was al-Farouk, a djinn (or spirit) who had watched over the city for many centuries.

Timbuktu’s fifty thousand or so inhabitants were in need of protection. Just weeks before, the city had been captured by Tuareg fighters who swept out of the deserts of northern Mali armed with weapons looted from Colonel Gaddafi’s armouries. The triumph of these ethnic nationalists was short-lived. Within days a coalition of Islamic militants terminated their chaotic rule. A mix of Malians, Algerians and others, many aligned with al-Qaeda, these extremists swiftly put an end to the looting that had broken out and re-established a semblance of order.

But if these acts reassured the local population and allowed the militants a short period in which to consolidate their authority, the calm did not last long. In Timbuktu, as in much of the Islamic world, the extremists were distressed to find that the Muslim faith was not practised in