Vientiane is the capital and largest city of Laos, situated in the Mekong river. Vientiane became the capital in 1563 due to fears of a Burmese invasion. During French rule, Vientiane was the administrative capital and due to economic growth in recent times, it has become the economic centre of Laos. The estimated population of the city is 754,000 (2009) while the number of people living in the Vientiane metropolitan area (the entire Vientiane Prefecture and parts of Vientiane Province) is believed to be over 730,000. The city hosted the 25th Southeast Asian Games in December 2009 celebrating the 50 years of SEA Games. Sri Sattanak, or Sisattanak, is a former name of Vientiane. It is often confused with Sri Sattanakanahut, the Pali name of Lan Xang, the Kingdom of the Million Elephants. Sisattanak now is the name of one of the five districts of the city Vientiane.