Chinese expansion under the Qin (221-206 BCE) and Han (206 BCE-220 CE) Dynasties is said to have been one of the primary impetuses for migrations to the Japanese archipelago, which brought with it cultural influences and new technologies.
The Chinese conquests during the Qin and Han periods are considered to have played a pivotal role in encouraging migrations to the Japanese islands, resulting in the introduction of cultural influences and new technologies.