The Republic of China, in the period up to 1949, was a sovereign state in East Asia that occupied the territories of modern China, and for part of its history Mongolia and Taiwan. It was founded in 1912, after the Qing dynasty, the last imperial dynasty, was overthrown in the Xinhai Revolution. The Republic's first president, Sun Yat-sen, served only briefly before handing over the position to Yuan Shikai, former leader of the Beiyang Army. His party, then led by Song Jiaoren, won the parliamentary election held in December 1912. Song was assassinated shortly after, and the Beiyang Army led by Yuan Shikai maintained full control of the government in Beijing. Between late 1915 and early 1916, Yuan tried to reinstate the monarchy, before abdicating after popular unrest. After Yuan's death in 1916, members of cliques in the former Beiyang Army claimed their autonomy and clashed with each other. During this period, the authority of the Beiyang government was weakened by a restoration of the Qing dynasty.