塘中
Đàng Ngoài was ruled by the Trịnh lords and the Lê dynasty, whose 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 Linh River (modern Gianh River in Quảng Bình Province). The name was gradually fading out from the people's memory after Nguyễn Huệ's conquering of the north.