For the celebration of the BBC's centenary, in this three part series David Dimbleby goes behind the scenes to investigate major controversies that have affected the BBC and its viewers over the last sixty years.

Aidan Hartley and Daniel Bogado gain rare access to the Nuba Mountains to film the heroic doctors who are saving children in a largely hidden war being perpetrated on civilians by one of the world’s most brutal dictatorships.

This documentary gains rare access to the Nuba Mountains to film the heroic doctors who are saving children in a largely hidden war being perpetrated on civilians by one of the world's most brutal dictatorships.