English sources from the People's Republic of China refer to the Gulf of Tonkin as Beibu Wan.[2][3]
Description and etymology
The name Tonkin, written "東京" in chữ Hán characters and Đông Kinh in the Vietnamese alphabet, means "eastern capital", and is the former toponym for Hanoi, the present capital of Vietnam. It is not to be confused with Tokyo, which is also written "東京" and also means "eastern capital". During the French colonial era, the northern region of today's Vietnam was called Tonkin.
Bắc Bộ is the native Vietnamese name of Tonkin, which is the nowadays region of Northern Vietnam. The bay's Vietnamese and Chinese names – Vịnh Bắc Bộ and Běibù Wān, respectively – both mean "Northern Bay".
The Gulf of Tonkin is a relatively shallow portion of the Pacific Ocean; the majority of the gulf's ocean floor is less than 75 metres (246ft) in depth, and no part of the gulf is submerged in more than 100 metres (330ft) of water.[4]
On 4 August 1964, United States PresidentLyndon B. Johnson claimed that North Vietnamese forces had twice attacked American destroyers in the Gulf of Tonkin.[5] Known today as the Gulf of Tonkin Incident, this event spawned the Gulf of Tonkin Resolution of 7 August 1964, ultimately leading to open war between North Vietnam and South Vietnam. It furthermore foreshadowed the major escalation of the Vietnam War in South Vietnam, which began with the landing of US regular combat troops at Da Nang in 1965.
Map of the maritime border between Vietnam and China in the Gulf of Tonkin. The red dot is Bach Long Vi Island
Maritime border issue in the Gulf of Tonkin
On December 25, 2000, Vietnam and China signed an Agreement on the Delimitation of the Gulf of Tonkin. An Agreement took effect on June 30, 2004, officially defining the maritime border between the two countries in the Gulf of Tonkin.[1][6]
The 2025 Vietnamese declaration on the baselines and width of territorial waters, which was made as a response to the parallel 2024 declaration from China. This map is wholly labeled in Vietnamese language and transcription.
On March 1, 2024, China issued a “Declaration on the baselines of the territorial waters in the northern part of the Gulf of Tonkin”.[7][8][9][10] Vietnam calls on China to respect international law.[7][10] One year later, in February 2025, Vietnam also announced baseline for determining its territorial waters width in the Gulf of Tonkin.[11]
Cooke, Nola; Li, Tana; Anderson, James A., eds. (2011). The Tongking Gulf Through History. Philadelphia, PA: University of Pennsylvania Press. ISBN978-0812243369.
Churchman, Catherine (2016). The People Between the Rivers: The Rise and Fall of a Bronze Drum Culture, 200–750 CE. Lanham, MD: Rowman & Littlefield. ISBN978-1442258600.
