The diplomatic relations between Chang’an (now Xi’an, Northwest China’s Shaanxi province) and Southeast Asia was mainly based on the Annan safeguard agency (located in present day Hanoi, Vietnam) during the Tang Dynasty (618-907).

The safeguard agency was set up to strengthen the local governance and help deal with the ethnic relationships, which partly contributed to the benign administration, economic development, and prosperous society in the early Tang Dynasty.

There were two routes from Chang’an to Southeast Asia, with one by land and the other by sea. The land route started from Chang’an to Myanmar, passing by Sichuan and Yunnan provinces. The sea route started from Guangzhou, Guangdong province, which was the major choice of that time.

During that time, several countries in Southeast Asia developed diplomatic relations with ancient China.

The diplomatic missions from Linyi, a country which was founded in Vietnam, visited Chang’an 35 times during the Tang Dynasty. The ancient laws and regulations of that time, as well as Buddhism, were spread to Vietnam.

Some poets of the Tang Dynasty also visited Vietnam to make exchanges with Vietnamese poets. Jiang Gongfu of Vietnam once served as a government official for Emperor Dezong of the Tang Dynasty.

Chenla (now Cambodia) made frequent trade exchanges with ancient China as well. A large number of Chinese goods were shipped to Chenla, such as gold, silver, silk, porcelain, and paper. The music and dances of Chenla were also spread to China, enriching the songs and dances of the Tang Dynasty.

The envoys from Pyu (now Myanmar) once sent 35 musicians and 22 compositions to give performances for Emperor Dezong of the Tang Dynasty, which caused a sensation in Chang’an.

Sumatra, Indonesia and Java both dispatched diplomatic missions to Chang’an with lots of specialties, such as cotton cloth, ivory, and sandals.

The systems and culture of ancient China made an impact on countries in Southeast Asia, and the culture of the Tang Dynasty was also influenced through the exchanges.