Annam was the name of the southernmost province of China after the Tang dynasty. The name is the Vietnamese form of the Chinese name "the Pacified South" (Chinese: ; pinyin: Ānnán; Vietnamese: An Nam), a clipped form of the full name, the "Protectorate General to Pacify the South" Chinese: ; pinyin: Ānnán Dūhùfǔ; Vietnamese: An Nam đô hộ phủ. This was one of a number of such protectorates formed by Tang China.
Before the establishment of the protectorate, the area was governed as Jiaozhou (, Jiāozhōu) or Jiaozhi (Chinese: ; pinyin: Jiāozhǐ; Vietnamese: Giao Chỉ). From its placement, it is now also sometimes known as Tonkin.
The territory was conquered for the Qin dynasty by Zhao Tuo after the death of Qin Shi Huang. In the chaos surrounding the Chu–Han Contention, he declared its independence as Nanyue and ruled from Panyu (modern Guangzhou). Jiaozhou was the Han dynasty country subdivision formed from the annexation of this tributary kingdom in 111 BCE and it initially comprised the areas of modern Guangdong, Guangxi, and northern Vietnam.