For 26 days in April 1917, Leon Bromstein Trotsky was known in Canada as POW #1098. On 29 April 1917, he and four fellow POWs were transferred from their internment camp in Amherst, Nova Scotia, and placed on board a steamer bound for Petrograd. World history might have been very different if Trotsky had not been released in 1917 but remained a POW in Canada until 1919, when many remaining POWs were repatriated to their country of origin. Relying on Canadian military archives, this presentation discusses Trotsky’s internment within the context of Canada’s First World War internment camps, revealing who was interned with him, how his wife and children were treated and describing the camp conditions where he was interned. Since 2016 Mark Minenko has reviewed tens of thousands of criminal case files, including the file of Leon Trotsky which forms the basis of this evening’s presentation.