In June 2014 Islamic State launched an astonishing blitzkrieg which saw them seize control of an area in the Middle East the size of Britain. The news was soon filled with their relentless acts of savagery, yet nobody seemed to know who they were or where they'd come from.

Now BBC reporter Andrew Hosken delivers the inside story on Islamic State. Through extensive first-hand reporting, Hosken builds a comprehensive picture of IS, their brutal ideology and extermination ist methods.

Equally compelling and horrifying, Empire of Fear reveals how Islamic State came to be, explores how they might be defeated and asks a frightening question - if they were brought down, could we stop another group emerging to replace them?