The Jeju Uprising was a popular rebellion that took place on the island of Jeju, South Korea, from April 3, 1948, to May 1949. The uprising was sparked by the decision of the newly-established Republic of Korea government to hold a controversial election for a National Assembly, which many on Jeju saw as a sham that would exclude left-leaning and progressive groups from the political process. The rebellion was led by the leftist and progressive groups who were against the government. The government responded by sending in the military to crush the rebellion, which resulted in a brutal crackdown that left thousands of people dead and many more injured. The suppression was marked by mass killings, torture, rape, and forced disappearances of tens of thousands of people, mostly civilians suspected of supporting the rebellion. The Jeju Uprising is considered a dark chapter in the history of South Korea and is still a sensitive subject today.