Komagata Maru, a Japanese-owned freighter chartered out of Hong Kong in April 1914 by 376 Punjabis, mostly Sikhs, bound for Canada. At the time, people from South Asia were kept out of Canada by an order-in-council requiring them to come to Canada by continuous passage from India, when no steamship line provided the service. Before the Canadian government, under tremendous pressure, closed the door in 1908, about 2,000 Sikhs had settled in British Columbia. In 1913, 38 Sikhs contested the continuous-passage order and were admitted. This encouraged others to charter the Komagata Maru.

When it arrived at Vancouver on 23 May 1914, most of the passengers were detained on board. They waited for two months while immigration officials maneuvered to keep them out of court and, after they had lost their case, while their leaders negotiated departure terms. The arrival of the RCN cruiser Rainbow on 20 July added to the Canadian pressure, and on 23 July the Komagata Maru sailed for Calcutta, where it was met by police suspicious of the organizers' politics. On disembarkation, 20 passengers were killed in a shooting exchange. The affair strengthened Indian nationalist feeling, but did not significantly soften Canadian immigration law.