In 1974 Souphanouvong returned to the Lao capital of Vientiane as chief of the Joint National Political Council. The Pathet Lao now dominated the government. On December 2, 1975, the monarchy was abolished and Prince Souphanouvong became the president of the newly proclaimed Lao People's Democratic Republic. He ran the country increasingly as a figurehead leader. In December 1978, Vietnamese soldiers based in southern Laos took part in the invasion of Cambodia. After suffering a stroke in September 1986, on October 31 of that year Prince Souphanouvong stepped down as president, remaining a member of the Politburo until 1991. He died on January 9, 1995.