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. Artifacts brought to the islands at this time had a powerful effect upon the development of Japanese art, by presenting objects to imitate and copy, such as bronze mirror,(Shinju-kyo) from Chinese mythology. The Yayoi people brought Japan into the Iron Age around the 3rd century CE.