Thanh Hóa Province in the context of Đại Ngu

Tonkin, also spelled Tongkin, Tonquin or Tongking, is an exonym referring to the area surrounding the Red River Delta of Northern Vietnam. During the 17th and 18th centuries, this term referred to the domain of Đàng Ngoài, under the control of the Trịnh lords, encompassing both the Northern and Thanh–Nghệ regions, north of the Gianh River at the 17.7th parallel. From 1884 to early 1945, the term referred to the French protectorate of Tonkin, which comprised only the Northern region, approximately north of the 20th parallel.

Bắc Trung Bộ (literally North Central Region, and often translated as North Central Coast) is one of the geographic regions of Vietnam. It consists of six provinces in northern part of Central Vietnam: Thanh Hóa, Nghệ An, Hà Tĩnh, Quảng Bình, Quảng Trị, Huế. The last two provinces were the northernmost provinces of State of Vietnam and South Vietnam until Reunification of Vietnam in 1976. In the Nguyễn dynasty, this area (except Thừa Thiên) was known as Hữu Trực Kỳ (the area located in the left of Thừa Thiên).

The Mường (Mường Bi dialect: mõl Mường; Vietnamese: người Mường) are an ethnic group native to northern Vietnam. The Mường is the country's third largest of 53 minority groups, with an estimated population of 1.45 million (according to the 2019 census). The Mường people inhabit a mountainous region of northern Vietnam centered in Hòa Bình Province and some districts of Phú Thọ province and Thanh Hóa Province. They speak the Mường language which is related to the Vietnamese language and the Thổ language and share ancient ethnic roots with the Vietnamese (Kinh) people.

The Hồ dynasty (Vietnamese: Nhà Hồ, chữ Nôm: 茹胡; Vietnamese: triều Hồ, chữ Hán: 朝胡), officially Đại Ngu (Vietnamese: Đại Ngu; chữ Hán: 大虞), was a short-lived Vietnamese dynasty consisting of the reigns of two monarchs, Hồ Quý Ly and his second son, Hồ Hán Thương. The practice of bequeathing the throne to a designated son (not simply passing it on to the eldest) was similar to what had happened in the previous Trần dynasty and was meant to avoid sibling rivalry. Hồ Quý Ly's eldest son, Hồ Nguyên Trừng, played his part as the dynasty's military general. In 2011, UNESCO declared the Citadel of the Hồ Dynasty in Thanh Hóa Province a world heritage site. The Hồ dynasty was conquered by the Chinese Ming dynasty in 1407.

Mường (thiếng Mươ̒ng; Vietnamese: tiếng Mường) is a group of dialects spoken by the Mường people of Vietnam. They are in the Austroasiatic language family and closely related to Vietnamese. According to Phan (2012), the Mường dialects are not a single language, or even most closely related to each other, but rather are an ethnically defined and paraphyletic taxon.

Mường dialects are primarily spoken in mountainous regions of the northern Vietnamese provinces of Hòa Bình, Thanh Hóa, Vĩnh Phúc, Yên Bái, Sơn La, and Ninh Bình.

Đông Sơn village (Vietnamese: làng Đông Sơn) is a small village on the banks of the Mã River in Hàm Rồng ward, Thanh Hóa city, Thanh Hóa Province. The village is best known for the discovery in 1924 of artifacts of what was later named Đông Sơn culture.

In 1924 a local fisherman stumbled on some bronze artifacts. On learning of the discovery the director of the École française d'Extrême-Orient, Léonard Eugène Aurousseau (1888-1929), instructed a local French customs official named Louis Pajot to investigate the location. Pajot immediately discovered numerous graves and set to work to excavate them. When the importance of the finds was realised the site was entrusted to professional archaeologists including Olov Janse.