The fall of the British empire is usually attributed to Nationalist groups fighting for independence, yet as Niall Ferguson argues in this final programme of the series, it was really due to the crippling cost of running the empire and financing the two World Wars. He reflects on the achievements and problems of the empire and concludes that in its twilight years Britain did more good than harm in fighting two far worse empires, namely Japan and Germany. Visiting some of the hot spots of the two World Wars and of the campaigns for independence that followed, such as Gallipoli, Istanbul, Suez, Amritsar and Singapore, presenter Niall Ferguson gives us a vivid picture of an empire on its last legs.

• Niall Ferguson