The House Divided follows these narratives from the first Sunni and Shia caliphates, through the medieval caliphates and empires of the Arabs, Persians and Ottomans, to the contemporary Middle East. It shows how a complex range of identities and rivalries - religious, ethnic and national - have shaped the region, jolted by the seismic shift of the Iranian Revolution of 1979. Rogerson's original approach takes the modern chessboard of nation states and looks at each through its particular history of empires and occupiers, minorities and resources, sheikhs and imams. The result is a book of wide-ranging empathy, understanding and insights.