Gia Long conquered Hanoi and unified modern-day Vietnam, which had experienced centuries of feudal warfare.

Gia Long, born Nguyễn Phúc Ánh (阮福暎) or Nguyễn Ánh (阮暎), was the founding emperor of the Nguyễn dynasty, the last dynasty of Vietnam, which would rule the unified territories that constitute modern-day Vietnam until 1945.

Hanoi is the capital and second-most populous city of Vietnam. The name "Hanoi" translates to "inside the river". As a municipality, since 2025, Hanoi consists of 51 wards and 75 communes. The city encompasses an area of 3,359.84 km² (1,297.24 sq mi). and as of 2025 has a population of 8,807,523. Hanoi had the second-highest gross regional domestic product of all Vietnamese provinces and municipalities at US$58,6 billion in 2025, behind only Ho Chi Minh City.