From March 1947 until 1987, Taiwan was in a state of martial law. Although the constitution provided for regular democratic elections, these were not held in Taiwan until the 1990s. In 1954, the Judicial Yuan ruled that the delegates elected to the National Assembly and Legislative Yuan in 1947 would remain in office until new elections could be held in Mainland China which had come under the control of the Communist Party of China in 1949. This judicial ruling allowed the Kuomintang to rule unchallenged in Taiwan until the 1990s. In the 1970s, supplemental elections began to be held for the Legislative Yuan. Although these were for a limited number of seats, they did allow for the transition to a more open political system. In 1991, these members were ordered to resign by a subsequent Judicial Yuan ruling.