On Saturday 12th April Sathnam Sanghera explores the events leading up to 1919's Jallianwala Bagh massacre, in which hundreds of peaceful protestors in Amritsar, India, were gunned down by British troops. Sathnam explores the implications of the killings on modern attitudes to the British Empire and travels to Punjab to meet descendants of the survivors. Catch The Massacre That Shook the Empire on Channel 4 at 9pm.