The Gaya Confederacy (42-562 CE) developed thanks to the abundant iron resources available in the mid- to lower regions of the Nakdonggang, formerly Byeonhan territory. In its early stages, Gaya was centered around Geumgwan Gaya in the Gimhae area of Gyeongsangnam-do, which became a hub of international trade, providing iron to Nangnang and ancient Japan via sea routes. In the late 3rd century CE, the region increased its power by embracing northern civilization, causing the center of activity to move northward to Dae Gaya in the Goryeong area of Gyeongsangbuk-do.

Excavations of Gaya sites have yielded pottery inscribed with the “Great King” (大王), as well as flamboyant gold crowns, demonstrating that the state was strong enough to compete against Silla and Baekje.

Gaya culture is characterized by stone chamber tombs that were dug vertically, various pottery with smooth curves, a proliferation of iron objects and weapons, and gold and silver inlay techniques. In particular, artifacts excavated from Gaya tombs in Daeseong-dong (Gimhae, Gyeongsangnam-do); Dohang-ri (Haman, Gyeongsangnam-do); Okjeon (Hapcheon, Gyeongsangnam-do); and Jisan-ri (Goryeong, Gyeongsangbuk-do) illustrate the magnificence of Gaya culture.