In a tumultuous period marked by rapid political changes, Liu Yu seized the imperial throne by usurping Emperor Gong of Jin, thereby proclaiming himself the first emperor of the Liu Song dynasty. This occurred during a time when the Jin dynasty was in considerable decline due to internal strife, power struggles, and the increasing pressure from various barbarian tribes. Liu Yu, a seasoned military commander, capitalized on the weaknesses of the Jin court, which had lost its grip over the southern territories. With a series of strategic campaigns and alliances, he managed to consolidate power and effectively remove Emperor Gong from the throne.

Following his proclamation, Liu Yu not only aimed to establish the legitimacy of his new dynasty but also sought to implement reforms that would stabilize the region. His reign was characterized by efforts to strengthen governance, improve agricultural productivity, and maintain military readiness against external threats. Liu Yu's rise to power is significant as it marks the beginning of the Liu Song dynasty, which would last for several decades and play an important role in the Southern Dynasties period of Chinese history, where various dynasties vied for control and influence over the region.

The transition from Jin to Liu Song also illustrates the shifting dynamics of power in China during this era, highlighting the fragility of imperial authority in the face of military might and political ambition. Liu Yu's establishment of the Liu Song dynasty not only reshaped the governance of southern China but also influenced subsequent dynasties and the larger narrative of Chinese imperial history as they sought to unify the country and manage regional differences.