Final answer:
In the Consolidation Period, the key players were the aristocrats from Northern China who reunified the former Han territory and established the Sui and Tang dynasties. Silla also played a significant role through its alliance with Tang and its adoption of Tang civilization and government.
Step-by-step explanation:
In the Consolidation Period (c. 500-780), the key players were the aristocrats from Northern China who reunified much of the former Han territory and established the Sui and Tang dynasties. The Tang dynasty, in particular, fought against the Koguryò and formed an alliance with Silla. Silla, in order to strengthen their alliance and centralize control, adopted many aspects of Tang civilization and government. However, despite the similarities in East Asian regimes, Silla's monarchs remained weaker, its aristocrats stronger, and its slaves more numerous.