Tonkin
ch 東京 dông kinh, 'Eastern Capital'.
Tonkin: Western rendition of 東京 Đông Kinh, 'Eastern Capital', the name of the capital city of the Lê dynasty (present-day Hanoi). In modern Vienam, Tonkin is known as miền Bắc, or Bắc Bộ (北部), 'Northern Region'.
Source
ADB Research team.
