Tonkin is a corruption of Đông Kinh, the name of Hà Nội during the Lê Dynasty. The Vietnamese refer to Tonkin as Bắc Kỳ meaning “Northern Region“. The region of Tonkin encompasses the Red River Delta Region of northern Vietnam. During French colonial rule, Vietnam was administratively divided into three different territories: Tonkin (in the north), Annam (in the centre), and the colony of Cochinchina (in the south). Hà Nội was the capital of the Tonkin territory, and in 1901 became the capital of all French Indochina (Cambodia, Laos, and Vietnam). French colonial administration ruled until 9 March 1945, allowed as a puppet government during Japanese occupation from 1941 to 1945. At the end of the Second World War, the north of Vietnam (including Tonkin) saw a sphere of influence by China while the south was briefly occupied by the British while French forces regrouped to regain control. In 1948, Tonkin was merged into the Provisional Central Government of Vietnam, which was replaced the next year by the State of Vietnam, following the reunification with Cochinchina. After the French defeat at the Battle of Điện Biên Phủ in Western Tonkin in 1954, the Communist state of the Democratic Republic of Vietnam (DRV) was formed, consisting of Tonkin and northern Annam.
