Although the cultural and demographic heritage of the southern river basins was distinct from that of the Central Plain and Yellow River basin, throughout the first millennium CE the South was undergoing an historic transformation as both cultural and demographic interaction with the Plain intensified. Although it began even before the Han dynasty, this interaction gained momentum after the early first millennium disaster connected with the usurpation of Wang Mang (45 BCE–23 CE), who briefly reigned as emperor of the Xin dynasty (r. 9–23 CE).

Even before Wang's usurpation and interregnum, emigrants from the North had trickled into the South. Much like the emigrants who made their way to North America many centuries later in search of security and new opportunities, they had been pushed by the increasingly oppressive exactions of northern landlords and pulled by the seductive promise of agricultural bounty. Also like those European migrants, these migrants were unprepared to recognize the indigenous folk they encountered as equally, or even fully, human. Thus as these migrants, following river valleys, found their way to the Yangtze basin, like those European migrants who had undertaken similarly perilous journeys, they presumed the land was theirs to take. And so the migration proceeded, via the north-flowing tributaries of the great river that had their sources in the southern mountains, all the way to the great southern port city known then as Panyu and more recently as Guangzhou (what European traders many centuries later called Canton, based on how they heard the regional pronunciation of Guangdong, the name of the province of which Panyu or Guangzhou has long been the capital).

Throughout the first millennium CE, these migrants lived alongside the indigenous peoples, sometimes peacefully but often not so. Whatever the nature of their interaction, however, gradually the cultures of both were transformed. Though some of the migrants came with backgrounds rooted in the elite customs of the north, by far the majority were common folk. Primarily they were peasants to whom the customs of the elite were as alien as were those of the southern cultures with which they found themselves enmeshed.