Gia Long in the context of "Đại Việt"

The Nguyễn dynasty (Vietnamese: Nhà Nguyễn or Triều Nguyễn, chữ Nôm: 茹阮, chữ Hán: 朝阮) was the last Vietnamese dynasty, preceded by the Nguyễn lords and ruling unified Vietnam independently from 1802 until the start of the French protectorate in 1883. Its emperors were members of the House of Nguyễn Phúc. During its existence, the Nguyễn empire expanded into modern-day Southern Vietnam, Cambodia, and Laos through a continuation of the centuries-long Nam tiến and Siamese–Vietnamese wars. With the French conquest of Vietnam, the Nguyễn dynasty was forced to give up sovereignty over parts of Southern Vietnam to France in 1862 and 1874, and after 1883 the Nguyễn dynasty only nominally ruled the French protectorates of Annam (Central Vietnam) as well as Tonkin (Northern Vietnam). Backed by Imperial Japan, in 1945 the last Nguyễn emperor Bảo Đại abolished the protectorate treaty with France and proclaimed the Empire of Vietnam for a short time until 25 August 1945.

The House of Nguyễn Phúc established control over large amounts of territory in Southern Vietnam as the Nguyễn lords (1558–1777, 1780–1802) by the 16th century before defeating the Tây Sơn dynasty and establishing their own imperial rule in the 19th century. The dynastic rule began with Gia Long ascending the throne in 1802, after ending the previous Tây Sơn dynasty. The Nguyễn dynasty was gradually absorbed by France over the course of several decades in the latter half of the 19th century, beginning with the Cochinchina Campaign in 1858 which led to the occupation of the southern area of Vietnam. A series of unequal treaties followed; the occupied territory became the French colony of Cochinchina in the 1862 Treaty of Saigon, and the 1863 Treaty of Huế gave France access to Vietnamese ports and increased control of its foreign affairs. Finally, the 1883 and 1884 Treaties of Huế divided the remaining Vietnamese territory into the protectorates of Annam and Tonkin under nominal Nguyễn Phúc rule. In 1887, Cochinchina, Annam, Tonkin, and the French Protectorate of Cambodia were grouped together to form French Indochina.

The Nguyễn lords (Vietnamese: Chúa Nguyễn, 主阮; 1558–1777, 1780–1802), also known as the Nguyễn clan (Vietnamese: Nguyễn thị; chữ Hán: 阮氏), were Nguyễn dynasty's forerunner and a feudal noble clan ruling southern Đại Việt in the Revival Lê dynasty. The Nguyễn lords were members of the House of Nguyễn Phúc. The territory they ruled was known contemporarily as Đàng Trong (Inner Realm) and known by Europeans as the Kingdom of Cochinchina and as Kingdom of Quảng Nam (Vietnamese: Quảng Nam Quốc; chữ Hán: 廣南國) by Imperial China, in opposition to the Trịnh lords ruling northern Đại Việt as Đàng Ngoài (Outer Realm), known as the "Kingdom of Tonkin" by Europeans and "Kingdom of Annam" (Vietnamese: An Nam Quốc; chữ Hán: 安南國) by Imperial China in bilateral diplomacy. They were officially entitled, in Sino-Vietnamese, the Nguyễn Vương (chữ Hán: 阮王) in 1744 when lord Nguyễn Phúc Khoát self-proclaimed himself to elevate his status equally to Trịnh lords's title known as the Trịnh Vương (Vietnamese: Trịnh Vương; chữ Hán: 鄭王). Both Nguyễn and Trịnh clans were de jure subordinates and fief of the Lê dynasty. However, the de jure submission of the Nguyễn lords to the Trịnh lords ended in 1627 sparked the war between them.

While they recognized the authority of and claimed to be loyal subjects of the revival Lê dynasty, they were de facto rulers of southern Đại Việt. Meanwhile, the Trịnh lords ruled northern Đại Việt in the name of the Lê emperor, who was in reality a puppet ruler. They fought a series of long and bitter wars that pitted the two halves of Vietnam against each other. The Nguyễn were finally overthrown in the Tây Sơn wars, but one of their descendants would eventually come to unite all of Vietnam. Their rule consolidated earlier southward expansion into Champa and pushed southwest into Cambodia.

The House of Nguyễn Phúc, also known as the House of Nguyễn Phước, is a family and a branch of the surname Nguyễn in Vietnam. Its members were the Nguyễn lords (1558–1777, 1780–1802) and emperors of the Nguyễn dynasty (1802–45). Its member Bảo Đại was also emperor of the State of Vietnam (1949–55) and Domain of the Crown (1950–55). Nguyễn Bặc (924–79), an official of the Đinh dynasty, was its founder.

Under Emperor Gia Long, the family's rule was not only restored, but extended to the whole of Vietnam in 1802, thus marking the start of the unified Nguyễn dynasty. The Nguyễn dynasty agreed to French supervision in 1883. In 1887, Vietnam became part of the Indochinese Union, which was administered by a French governor general.

The Tây Sơn dynasty (Vietnamese: [təj ʂəːn]; Vietnamese: "Nhà Tây Sơn" or "Triều Tây Sơn", (chữ Hán: 朝西山; Chữ Nôm: 茹西山), officially Đại Việt (Chữ Hán: 大越), was an imperial dynasty of Vietnam. It originated in a revolt led by three peasant brothers with the surname Nguyễn, rebelling against the Lê dynasty, Trịnh lords and Nguyễn lords (no relation). The Tây Sơn would later be succeeded by the Nguyễn dynasty.

The Tây Sơn dynasty ended the century-long war between the Trịnh and Nguyễn families, overthrew the Lê dynasty, and united the country for the first time in 200 years. They acknowledged Qing suzerainty and gained recognition from the Qianlong Emperor as the legitimate rulers of Vietnam. Under the most prominent of the Tây Sơn brothers Nguyễn Huệ (Emperor Quang Trung) Vietnam experienced several years of relative peace and prosperity. But Quang Trung died relatively young at the age of 40 and his successor Cảnh Thịnh, aged 9, was unable to prevent civil conflict among the Tây Sơn court which allowed the last Nguyễn lord Nguyễn Ánh to retake the south of Vietnam, extinguish the Tây Sơn and establish the Nguyễn dynasty.

Đàng Ngoài (chữ Hán: 唐外, lit. "Outer Land"), also known as Bắc Hà (北河, "North of the River") or Kingdom of Annam (安南國) by foreigners, was an area in northern Đại Việt (now Vietnam) during the 17th and 18th centuries as the result of Trịnh–Nguyễn War. The name Đàng Ngoài was first recorded in the Dictionarium Annamiticum Lusitanum et Latinum by Alexandre de Rhodes.

Đàng Ngoài was de facto ruled by the Trịnh lords with the Lê emperors acting as titular rulers. The 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 Gianh River in Quảng Bình province. The names gradually fell into disuse after Nguyễn Ánh reunified Đại Việt.