The sixth century was an important stage in the Vietnamese political evolution toward independence. During this period, the Vietnamese aristocracy, while retaining Chinese political and cultural forms, grew increasingly independent of China. In the period between the beginning of the Chinese Age of Fragmentation and the end of the Tang dynasty, several revolts against Chinese rule took place. In 543, Lý Bí and his brother Lý Thiên Bảo revolted against the Chinese Liang dynasty and briefly ruled an independent Van Xuan kingdom for almost half a century, from 544 to 602, before Sui China reconquered the kingdom.^[72]