The formation of the Gaya Confederacy is marked by the founding of Geumgwan Gaya by King Suro in 42 AD. This event was rooted in the rich iron culture and maritime trade traditions of Byeonhan, located in the southern Korean Peninsula, particularly the lower Nakdong River basin. The Byeonhan region had long developed advanced iron production and processing technologies, enjoying economic prosperity by exporting iron not only to neighboring states but also to the Japanese archipelago. Against this backdrop, as various small states competed, the stage was set for the emergence of a powerful leadership. According to legend, in 42 AD, King Suro, born from a golden egg descended from heaven at Guji Peak, founded Garakguk (Geumgwan Gaya). King Suro unified nine surrounding villages and laid the foundation of the state with his outstanding governance. Geumgwan Gaya rapidly grew based on the fertile lands of the Nakdong River estuary and abundant iron production, establishing itself as the leader (maengju) of the Gaya Confederacy, encompassing various surrounding Gaya small states. Unlike centralized ancient kingdoms, this confederacy maintained the independence of each small state while fostering economic and military cooperation centered around Geumgwan Gaya. Iron culture was the core driving force of the Gaya Confederacy, engaging in active foreign trade based on its excellent iron-making technology and iron production capacity. The formation of the Gaya Confederacy holds significant meaning in the ancient history of the Korean Peninsula. First, it blossomed iron culture, greatly contributing to the development of East Asian iron civilization. Gaya's iron profoundly influenced the formation of ancient Japanese states. Second, it maintained a unique culture and political system between the great states of Baekje and Silla, acting as a balance wheel in the southern Korean Peninsula. Third, as a hub for maritime trade, it served as a channel for cultural exchange connecting the Korean Peninsula, Japan, and China. Although the Gaya Confederacy eventually disappeared into history, absorbed by Silla in the mid-6th century, its unique cultural heritage and iron technology are still regarded as a crucial pillar of ancient Korean history today.