Sui dynasty China had a population of about 45 million at its peak .
Despite its brevity , the Sui reunified China , and its laws and administration formed the basis of the later Tang , Song and Ming dynasties .
Sui   China had a population of about 45 million at China 's peak .
Despite its brevity , the Sui reunified China , and its laws and administration formed the basis of the later Tang , Song and Ming dynasties .