Myanmar, officially the Republic of the Union of Myanmar and formerly known as Burma, is a sovereign state in Southeast Asia. Myanmar is bordered by India and Bangladesh to its west, Thailand and Laos to its east and People's Republic of China to its north and northeast. To its south, about one third of Myanmar's total perimeter of 5,876 km forms an uninterrupted coastline of 1,930 km along the Bay of Bengal and the Andaman Sea. The country's 2014 census counted the population to be 51 million people. As of 2017, the population is about 54 million. Myanmar is 676,578 square kilometres in size. Its capital city is Naypyidaw, and its largest city and former capital is Yangon. Myanmar has been a member of the Association of Southeast Asian Nations since 1997.
Early civilisations in Myanmar included the Tibeto-Burman-speaking Pyu city-states in Upper Burma and the Mon kingdoms in Lower Burma. In the 9th century, the Bamar people entered the upper Irrawaddy valley and, following the establishment of the Pagan Kingdom in the 1050s, the Burmese language, culture and Theravada Buddhism slowly became dominant in the country.