Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of Mainland Southeast Asia. With an area of about 331,000 square kilometres (128,000 sq mi) and a population of over 100 million, it is the world's 15th-most populous country. One of two communist states in Southeast Asia, Vietnam is bordered by China to the north, Laos and Cambodia to the west, the Gulf of Thailand to the southwest, and the South China Sea to the east; it also shares maritime borders with Thailand, Malaysia, and Indonesia to the south and southwest, the Philippines to the east, and China to the northeast. Its capital is Hanoi, while its largest city is Ho Chi Minh City.
Vietnam was inhabited by the Paleolithic age, with states established in the first millennium BC on the Red River Delta in modern-day northern Vietnam. The Han dynasty annexed northern and central Vietnam, which were subsequently under Chinese rule from 111 BC until the first dynasty emerged in 939. Successive monarchical dynasties absorbed Chinese influences through Confucianism and Buddhism, and expanded southward to the Mekong Delta, conquering Champa. During most of the 17th and 18th centuries, Vietnam was effectively divided into two domains of Đàng Trong and Đàng Ngoài. The Nguyễn—the last imperial dynasty—surrendered to France in 1883. In 1887, its territory was integrated into French Indochina as three separate regions. In the immediate aftermath of World War II, the Viet Minh, a coalition front led by the communist revolutionary Ho Chi Minh, launched the August Revolution and declared Vietnam's independence from the Empire of Japan in 1945.