Tonkin in the context of "Gulf of Tonkin"

Northern Vietnam or Tonkin (Vietnamese: Bắc Bộ) is one of three geographical regions in Vietnam. It consists of three geographic sub-regions: the Northwest (Vùng Tây Bắc), the Northeast (Vùng Đông Bắc), and the Red River Delta (Đồng Bằng Sông Hồng). It is near China. Unlike tropical Central and Southern Vietnam, Northern Vietnam has a subtropical climate.

It has a total area of about 109,942.9 km. The region's largest city, Hanoi, serves as the country's capital. Among the three geographical regions, the oldest is Northern Vietnam. Vietnamese culture originated in the Red River Delta and the Kinh Vietnamese eventually spread south into the Mekong Delta.

The French conquest of Vietnam (1858–1885) was a series of military expeditions that pitted the Second French Empire, later the French Third Republic, against the Vietnamese empire of Đại Nam in the mid-late 19th century. Its end results were victories for France as they defeated the Vietnamese and their Chinese allies in 1885, incorporated modern-day Vietnam, Laos, and Cambodia into the French colonial empire, and established the territory of French Indochina over Mainland Southeast Asia in 1887.

A joint Franco-Spanish expedition was initiated in 1858 by invading Tourane (modern day Da Nang) in September 1858 and Saigon five months later. This four-year campaign resulted in Emperor Tu Duc signing a treaty in June 1862, granting the French sovereignty over three provinces in the South. The French annexed the three southwestern provinces in 1867 to form Cochinchina. Having consolidated their power in Cochinchina, they conquered the rest of Vietnam through a series of campaigns in Tonkin between 1873 and 1886. French ambitions to subjugate Tonkin were opposed by the Qing dynasty, the region being part of the Chinese sphere of influence.

Cochinchina or Cochin-China (/ˌkoʊtʃɪnˈtʃaɪnə/, UK also /ˌkɒtʃ-/; Vietnamese: Đàng Trong (17th–18th centuries), Việt Nam (1802–1831), Đại Nam (1831–1862), Nam Kỳ (1862–1945); Khmer: កូសាំងស៊ីន, romanized: Kosăngsin; French: Cochinchine; Chinese: 交趾支那; pinyin: Jiāozhǐ zhīnà) is a historical exonym for part of Vietnam, depending on the contexts, usually for Southern Vietnam. Sometimes it referred to the whole of Vietnam, but it was commonly used to refer to the region south of the Gianh River.

In the 17th and 18th centuries, Vietnam was divided between the Trịnh lords to the north and the Nguyễn lords to the south. The two domains bordered each other on the Son River. The northern section was called Tonkin by Europeans, and the southern part, Đàng Trong, was called Cochinchina by most Europeans and Quinam by the Dutch.

Đàng Ngoài (chữ Hán: 唐外, lit. "Outer Land"), also known as Bắc Hà (北河, "North of the River") or Kingdom of Annam (安南國) by foreigners, was an area in northern Đại Việt (now Vietnam) during the 17th and 18th centuries as the result of Trịnh–Nguyễn War. The name Đàng Ngoài was first recorded in the Dictionarium Annamiticum Lusitanum et Latinum by Alexandre de Rhodes.

Đàng Ngoài was de facto ruled by the Trịnh lords with the Lê emperors acting as titular rulers. The capital was Thăng Long (now Hanoi). Thăng Long was also known as Đông Kinh 東京, meaning "Eastern Capital", from which the common European name for Đàng Ngoài "Tonkin" originated. It was bordered by Đàng Trong (under the Nguyễn lords) along the Gianh River in Quảng Bình province. The names gradually fell into disuse after Nguyễn Ánh reunified Đại Việt.

The Tonkin campaign was an armed conflict fought between June 1883 and April 1886 by the French against, variously, the Vietnamese, Liu Yongfu's Black Flag Army and the Chinese Guangxi and Yunnan armies to occupy Tonkin (northern Vietnam) and entrench a French protectorate there. The campaign, complicated in August 1884 by the outbreak of the Sino-French War and in July 1885 by the Cần Vương nationalist uprising in Annam (central Vietnam), which required the diversion of large numbers of French troops, was conducted by the Tonkin Expeditionary Corps, supported by the gunboats of the Tonkin Flotilla. The campaign officially ended in April 1886, when the expeditionary corps was reduced in size to a division of occupation, but Tonkin was not effectively pacified until 1896.

Paul Mus (1902–1969) was a French writer and scholar. His studies focused on Vietnam and other Southeast Asian cultures.

He was born in Bourges to an academic family, and grew up in northern Vietnam (Tonkin). In 1907 his father opened the College de Protectorate in Hanoi and he would graduate from the college some 12 years later.

The Franco-Siamese crisis of 1893, known in Thailand as the Incident of Rattanakosin Era 112 (Thai: วิกฤตการณ์ ร.ศ. 112,RTGS: wikrittakan roso-roisipsong, [wí krít tàʔ kaːn rɔː sɔ̌ː rɔ́ːj sìp sɔ̌ːŋ]) was a conflict between the French Third Republic and the Kingdom of Siam. Auguste Pavie, French vice-consul in Luang Prabang in 1886, was the chief agent in furthering French interests in Laos. His intrigues, which took advantage of Siamese weakness in the region and periodic invasions by Vietnamese rebels from Tonkin, increased tensions between Bangkok and Paris. The conflict concluded with the Paknam Incident, in which French gunboats sailed up the Chao Phraya River to blockade Bangkok. The Siamese subsequently agreed to cede the area that constitutes most of present-day Laos to France, an act that led to the significant expansion of French Indochina.

This conflict succeeded the Haw wars (1865–1890), in which the Siamese attempted to pacify northern Siam and Tonkin.

The Haw Wars (Thai: สงครามปราบฮ่อ) were fought against Chinese quasi-military refugee gangs invading parts of Tonkin and Laos from 1865–1890. Forces invading Lao domains were ill-disciplined and freely demolished Buddhist temples. Not knowing these were remnants of secret societies, the invaders were wrongly called Haw (Lao: ຫໍ້; Thai: ฮ่อ; Chinese: Hao). Forces sent by King Rama V failed to suppress the various groups, the last of which eventually disbanded in 1890.