The Sui dynasty (581–618 CE) was the short-lived Chinese imperial dynasty that reunified the country after nearly three centuries of division. Yang Jian founded it in 581 by seizing the throne of a northern state, and ruling as Emperor Wen he completed the reunification only in 589, when his armies conquered the southern Chen. In under four decades the Sui rebuilt a strong central government and vast public works, then collapsed under forced labor and failed foreign wars. Its institutions were inherited and adapted by the long-lived Tang dynasty that replaced it.
In 605 the second Sui emperor drove huge levies of conscripted laborers, reportedly numbering in the millions, to link and extend the older canals of China into one continuous waterway. The Grand Canal ran more than a thousand miles, carrying southern rice to the northern capitals and knitting a reunited empire into one body. It also broke the backs that dug it. Within thirteen years the dynasty that built it was gone, toppled by revolt, and the canal outlived that dynasty by more than a thousand years.