Emperor Wen of Sui (541-604); personal name Yang Jian; was the founder and first emperor of China's Sui Dynasty (581-618). He was a hard-working administrator. As a Buddhist; he encouraged the spread of Buddhism through the state. Emperor Wen's reign introduced a period of great prosperity not seen since the Han Dynasty. Economically; the dynasty prospered. It was said that there was enough food stored for 50 years. The military was also powerful.

At the beginning of his reign; Sui faced the threat of Tujue to the north; and neighboring Tibetan tribes to the west; Goguryeo in the northeast; and the kingdom known as Linyi (Champa) to the south. By the end of Emperor Wen's reign; Tujue had split into an eastern and a western kaganate; the eastern one being nominally submissive to Sui; as was Goguryeo. Linyi was defeated and; while not conquered; did not remain a threat.