Tonkin

Tonkin, also spelled Tongking, is the northernmost part of Vietnam, south of China's Yunnan and Guangxi Provinces, east of northern Laos, and west of the Gulf of Tonkin. Locally, it is known as Bắc Bộ (北圻), meaning "Northern Boundary". Located on the fertile delta of the Red River, Tonkin is rich in rice production.

Hanoi has been the capital of the Chinese Tonkin since the 7th century, when it was called Dongjing (東京), meaning "Eastern Capital." "Tonkin" is the Vietnamese pronunciation of "Dongjing." (The same characterss are used to write the name of the city of Tokyo.)

France assumed sovereignty over Annam and Tonkin after the Franco-Chinese War (1884-1885). The French used the name of the capital for the entire region under its jurisdiction. The third part of Vietnam were was Cochin China at the south.

The Latin adjective tonkinensis is a specific epithet, part of the binomial nomenclature, used to describe species, mostly trees, found in Tonkin. For example, Cornus hongkongensis subsp. tonkinensis [1] is a subspecies of an evergreen tree or shrub of the dogwood family that is usually found in Hong Kong, but this particularly subpecies have been located in Tonkin.

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Tonkin is a very rare Romanization of Tokyo, possibly based on Korean or Chinese.