Taiwan was part of China until the Qing dynasty fell in 1911. Afterward, Taiwan was ruled by Japan for 50 years before it was returned to China in 1945. Since then, there has been a complicated relationship between Taiwan and the mainland Chinese government, with both claiming sovereignty over the island. In 1949, the Communist Party of China won the Chinese Civil War and established control over mainland China. At this time, most of the people on Taiwan supported the Republic of China (ROC) government, which fled to Taiwan after losing the war.