Cantonese is believed more related to the old "Qin-Han Dynasty" languages as it preserve some of the unique words and pronunciations. GuanDong remain a popular dialect in southern region and many other overseas chinatowns
Modern Chinese aka Pu Tong Hua is a northern dialect that is popularised after Yuan Dynasty. In addition, Ming Cheng Zhu shifted Ming political center from Nanking to Peking - former Yuan Capital site, catalyzed the importance of this northern dialect throughout the empire from 15th century.