In the time of King Zhou Xuandi, the military power of Northern Zhou was actually
under the hand of Yang Jian. In 580, Zhou Xuandi died and the dynasty announced
King Zhou Jingdi. The next year, Yang Jian forced Zhou Jingdi to give out his
throne. Yang Jian then founded the dynasty Sui and ascended to the kingship. In
589, Yang Jian, i.e. King Sui Wendi, occupied Jiankang, capital of the Chen Dynasty.
With the last of the southern dynasties (the Song, Qi, Liang and Chen Dynasties)
dying out, China unified again into the Sui Dynasty.
To consolidate his rule over the new dynasty, King Sui Wendi reformed the official
structure and military systems, punished the corrupt, abolished cruel tortures
to the guilty, and freed people from forced labor. Meanwhile, he formed the
imperial-examination system for the first time in Chinese history, which assured
the fairness of talented people into the government. Gradually, the Sui Dynasty
restored from the civil war and began to thrive.
But at the same time the nomad nationality Tujue harassed frequently about
Sui's north borderline from Youzhou to the west West Regions. To resist Tujue's
invasion, Sui Dynasty requisitioned large numbers of labors to repair and build
walls for several times. The walls are as follows:
** In April 581, Sui ordered Jihu, one descendant of South Hun, to build walls.
This construction was limited to 20 days.
** In December 581, Sui repaired the eastern parts of the Northern Wei and
Northern Qi Dynasty.
** In 585, Sui requisitioned 30,000 labors to fix the wall running from eastern
bank of the Yellow River in Linwu of Ningxia Hui Autonomous Region to present
Suide of Shannxi Province. This part of wall extended from east to west about
** In 586, Sui repaired its walls thoroughly within 20 days. Meanwhile, to
protect its borderline, Sui built more than ten fortresses along the east part
of wall in present Henshan County of Shannxi.
** It is recorded in one literature that "in 587, Sui requisitioned more
than 100,000 labors to fix up the wall within 20 days." But the starting
point and destination of this construction are not mentioned.
** In July 607, Sui ordered more than 1,000,000 labors to build the wall running
east from present Yulin of Shannxi Province to the bank of Hunhe River. The
whole construction was limited to 10 days.
** In July 608, Sui ordered 200,000 labors to build the wall starting at present
Xining of Qinhai Province. The wall went east, but the destination is not recorded
in historical materials.