**30 April 1924.** At the Court of the King’s Bench in London, the highest court in the Empire, an English judge and jury heard the case that would change the course of India’s history: Sir Michael O’Dwyer, the former Lieutenant Governor of the Punjab – and architect of the infamous Jallianwala Bagh massacre – had filed a defamation case against Sir Chettur Sankaran Nair for having published a book in which he referred to the atrocities committed by the Raj in Punjab. The widely-reported trial – one of the longest in history – stunned a world that finally recognized some of the horrors being committed by the British in India. Through reports of court proceedings along with a nuanced portrait of a complicated nationalist who believed in his principles above all else, *The Case That Shook the Empire* reveals, for the very first time, the real details of the fateful case that marked the defining moment in India’s struggle for Independence.