Nam tiến refers to the southward expansion of the territory of Vietnam

Vietnam

Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...

 from the 11th century to the mid-18th century. The territory of Vietnam was gradually expanded to the South from its original heartland in the Red River Delta

Red River Delta

The Red River Delta is the flat plain formed by the Red River and its distributaries joining in the Thai Binh River in northern Vietnam. The delta measuring some 15,000 square km is well protected by a network of dikes. It is an agriculturally rich area and densely populated...

. After nearly 700 years, Vietnam's territory was increased by three times and almost had the current shape.

The direction of expansion was to the south because Annam, as Vietnam was known at that time, was surrounded by the sea to the East, by a mountainous area to the West, and by a powerful country to the North, China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

. This Vietnamese "drive to the south" was no different than the German Drang nach Osten

Drang nach Osten

Drang nach Osten was a term coined in the 19th century to designate German expansion into Slavic lands. The term became a motto of the German nationalist movement in the late nineteenth century...

 or the American Westward Expansion (1789–1849).