Given the following passage "At the beginning of the Three Kingdoms era (220280 CE), Zhejiang was home to the warlords Yan Baihu and Wang Lang prior to their defeat by Sun Ce and Sun Quan, who eventually established the Kingdom of Wu. Despite the removal of their court from Kuaiji to Jianye (present-day Nanjing), they continued development of the region and benefitted from influxes of refugees fleeing the turmoil in northern China. Industrial kilns were established and trade reached as far as Manchuria and Funan (south Vietnam).", answer the following question. Note that the answer is present within the text. Question: Where did the immigrants come from?
The answer to this question is:
northern China