French Indochina in the context of "First Indochina War"

The French colonial empire (French: Empire colonial français) consisted of the overseas colonies, protectorates, and mandate territories that came under French rule from the 16th century onward. A distinction is generally made between the "First French colonial empire", that existed until 1814, by which time most of it had been lost or sold, and the "Second French colonial empire", which began with the conquest of Algiers in 1830. On the eve of World War I, France's colonial empire was the second-largest in the world after the British Empire.

France began to establish colonies in the Americas, the Caribbean, and India in the 16th century but lost most of its possessions after its defeat in the Seven Years' War. The North American possessions were lost to Britain and Spain, but Spain later returned Louisiana to France in 1800. The territory was then sold to the United States in 1803. France rebuilt a new empire mostly after 1850, concentrating chiefly in Africa as well as Indochina and the South Pacific. As it developed, the new French empire took on roles of trade with the metropole, supplying raw materials and purchasing manufactured items. Especially after the disastrous Franco-Prussian War, which saw Germany become the leading economic and military power of the continent of Europe, acquiring colonies and rebuilding an empire was seen as a way to restore French prestige in the world. It was also to provide manpower during the world wars.

The civilizing mission (Spanish: misión civilizadora; Portuguese: Missão civilizadora; French: Mission civilisatrice) is a political rationale for military intervention and for colonization purporting to facilitate the cultural assimilation of indigenous peoples, especially in the period from the 15th to the 20th centuries. As a principle of Western culture, the term was most prominently used in justifying French colonialism in the late-15th to mid-20th centuries. The civilizing mission was the cultural justification for the colonization of French Algeria, French West Africa, French Indochina, Portuguese Angola and Portuguese Guinea, Portuguese Mozambique and Portuguese Timor, among other colonies. The civilizing mission also was a popular justification for the British and German colonialism. In the Russian Empire, it was also associated with the Russian conquest of Central Asia and the Russification of that region. The Western colonial powers claimed that, as Christian nations, they were duty bound to disseminate Western civilization to what they perceived as heathen, primitive cultures. It was also applied by the Empire of Japan, which colonized Korea.

The attack on Pearl Harbor was a surprise military strike by the Empire of Japan on the United States Pacific Fleet at its naval base at Pearl Harbor on Oahu, Hawaii, on December 7, 1941. At the time, the U.S. was a neutral country in World War II. The air raid on Pearl Harbor, which was launched from aircraft carriers, resulted in the U.S. declaring war on Japan the next day. The Japanese military leadership referred to the attack as the Hawaii Operation and Operation AI, and as Operation Z during its planning.

The attack on Pearl Harbor was preceded by months of negotiations between the U.S. and Japan over the future of the Pacific. Japanese demands included that the U.S. end its sanctions against Japan, cease aiding China in the Second Sino-Japanese War, and allow Japan to access the resources of the Dutch East Indies. Japan sent out its naval attack group on November 26, 1941, just prior to receiving the Hull note, which stated the U.S. desire that Japan withdraw from China and French Indochina. Isoroku Yamamoto, commander of the Japanese Combined Fleet, planned the attack as a pre-emptive strike on the Pacific Fleet, based at Pearl Harbor since 1940 in order to prevent it from interfering with Japan's planned actions in Southeast Asia. Yamamoto hoped that the strike would enable Japan to make quick territorial gains and negotiate peace. In addition to Pearl Harbor, over seven hours Japan launched coordinated attacks on the U.S.-held Philippines, Guam, and Wake Island; and on the British Empire in Malaya, Singapore, and Hong Kong.

The Nguyễn dynasty (Vietnamese: Nhà Nguyễn or Triều Nguyễn, chữ Nôm: 茹阮, chữ Hán: 朝阮) was the last Vietnamese dynasty, preceded by the Nguyễn lords and ruling unified Vietnam independently from 1802 until the start of the French protectorate in 1883. Its emperors were members of the House of Nguyễn Phúc. During its existence, the Nguyễn empire expanded into modern-day Southern Vietnam, Cambodia, and Laos through a continuation of the centuries-long Nam tiến and Siamese–Vietnamese wars. With the French conquest of Vietnam, the Nguyễn dynasty was forced to give up sovereignty over parts of Southern Vietnam to France in 1862 and 1874, and after 1883 the Nguyễn dynasty only nominally ruled the French protectorates of Annam (Central Vietnam) as well as Tonkin (Northern Vietnam). Backed by Imperial Japan, in 1945 the last Nguyễn emperor Bảo Đại abolished the protectorate treaty with France and proclaimed the Empire of Vietnam for a short time until 25 August 1945.

The House of Nguyễn Phúc established control over large amounts of territory in Southern Vietnam as the Nguyễn lords (1558–1777, 1780–1802) by the 16th century before defeating the Tây Sơn dynasty and establishing their own imperial rule in the 19th century. The dynastic rule began with Gia Long ascending the throne in 1802, after ending the previous Tây Sơn dynasty. The Nguyễn dynasty was gradually absorbed by France over the course of several decades in the latter half of the 19th century, beginning with the Cochinchina Campaign in 1858 which led to the occupation of the southern area of Vietnam. A series of unequal treaties followed; the occupied territory became the French colony of Cochinchina in the 1862 Treaty of Saigon, and the 1863 Treaty of Huế gave France access to Vietnamese ports and increased control of its foreign affairs. Finally, the 1883 and 1884 Treaties of Huế divided the remaining Vietnamese territory into the protectorates of Annam and Tonkin under nominal Nguyễn Phúc rule. In 1887, Cochinchina, Annam, Tonkin, and the French Protectorate of Cambodia were grouped together to form French Indochina.

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.

Hanoi (/hæˈnɔɪ/ han-OY; Vietnamese: Hà Nội [hàː nôjˀ] ) is the capital and second-most populous city of Vietnam. The name "Hanoi" translates to "inside the river" (Hanoi is bordered by the Red and Black Rivers). The city encompasses an area of 3,358.6 km (1,296.8 sq mi), and as of 2025 has a population of 8,807,523. Hanoi had the second-highest gross regional domestic product of all Vietnamese provinces and municipalities at US$48 billion in 2023, behind only Ho Chi Minh City.

In the third century BCE, the Cổ Loa Capital Citadel of Âu Lạc was constructed in what is now Hanoi. Âu Lạc then fell under Chinese rule for a thousand years. In 1010, under the Lý dynasty, Vietnamese emperor Lý Thái Tổ established the capital of the imperial Vietnamese nation Đại Việt in modern-day central Hanoi, naming the city Thăng Long [tʰɐŋ loŋ], 'ascending dragon'). In 1428, King Lê Lợi renamed the city to Đông Kinh [ɗoŋ kīŋ̟], 'eastern capital'), and it remained so until 1789. The Nguyễn dynasty in 1802 moved the national capital to Huế and the city was renamed Hanoi in 1831. It served as the capital of French Indochina from 1902 to 1945 and French protectorate of Tonkin from 1883 to 1949. After the August Revolution and the fall of the Nguyễn dynasty, the Democratic Republic of Vietnam (DRV) designated Hanoi as the capital of the newly independent country. From 1949 to 1954, it was part of the State of Vietnam. It was again part of the DRV ruling North Vietnam from 1954 to 1976. In 1976, it became the capital of the unified Socialist Republic of Vietnam. In 2008, Hà Tây Province and two other rural districts were annexed into Hanoi, almost tripling Hanoi's area.

Haiphong or Hai Phong (Vietnamese: Hải Phòng, pronounced [hǎːj fɔ̀ŋ͡m] ) is the third-largest city in Vietnam and is the principal port city of the Red River Delta. The municipality has an area of 1,526.52 km (589.39 sq mi). The city includes Bạch Long Vĩ and Cát Hải islands in the Gulf of Tonkin. It has a population of 2,130,898 in 2023. The city's economy has strength in manufacturing, as evidenced by large industrial parks and numerous smaller traditional handicraft villages. Historically, Haiphong was the first place in Vietnam and Mainland Southeast Asia to get electricity.

In the imperial era of Đại Việt, the Bạch Đằng River in Haiphong was a place of many legendary victories, led by now-legendary commanders Ngô Quyền and Trần Hưng Đạo. In the 16th century, Mạc dynasty promoted the coastal settlement as a secondary capital, growing to become an important port town of Đàng Ngoài. After the French conquest of Vietnam, in 1888, the president of the French Third Republic, Sadi Carnot, promulgated a decree to establish Haiphong as one of the principal cities of French Indochina. From 1954 to 1975, Haiphong served as the most important maritime city of North Vietnam. It was one of the directly controlled municipalities of a reunified Vietnam with Hanoi and Ho Chi Minh City in 1976.

A yamen (ya-men; traditional Chinese: 衙門; simplified Chinese: 衙门; pinyin: yámén; Wade–Giles: ya-men; Manchu: ᠶᠠᠮᡠᠨyamun) was the administrative office or residence of a local bureaucrat or mandarin in imperial China, Korea, and Vietnam. In some places, such as Kowloon Walled City, Hong Kong, it was named as almshouse. A yamen can also be any governmental office or body headed by a mandarin, at any level of government: the offices of one of the Six Ministries is a yamen, but so is a prefectural magistracy. The term has been widely used in China for centuries, but appeared in English during the Qing dynasty.