Iron Age
Iron arrived around the 5th century BCE and began to be used for farm tools and weapons; on this base several states arose.
Iron farm tools raised harvests and iron weapons spurred conquest. Bronze became mainly ritual: on the peninsula the mandolin-shaped dagger gave way to the slender Korean-type dagger and the coarse-patterned mirror to the fine-patterned mirror. Casting moulds show these were made locally. Pottery included rim-banded and black burnished wares, and burials were in wooden coffins and jar coffins.
Contact with China grew. Chinese coins — mingdao, banliang and wuzhu — have been found at many sites, and writing brushes from Daho-ri in Changwon show that Chinese characters were in use.
Iron culture underpinned the growth of Gojoseon (Wiman’s rule); after its fall Buyeo, Goguryeo, Okjeo, Dongye and the Samhan took shape across Manchuria and the peninsula.