Formation of iron production workshops and Trends of Ironworking Communities in the Inland Region of Hoseo during the Mahan Period

Iron production sites from the Proto–Three Kingdoms period in the inland region of Hoseo are primarily distributed along the Miho River and Namhan River basins. These sites exhibit a production system centered on wrought iron manufacturing. Smelting furnaces reveal regional differences in tuyère structures between the two areas, and timber reinforcements were installed in substructure levels to stabilize the furnace architecture. The development of ironworking facilities in this region can be divided into three phases. In Phase I (ca. late 2nd century BCE to early 2nd century CE), ironworking was first introduced into Mahan society, leading to the establishment of production facilities at key locations such as Songjeol-dong in Cheongju and Chilgeum-dong in Chungju. Phase II (ca. late 2nd to early 3rd century CE) is characterized by increasing demand for iron within Mahan, resulting in the spatial expansion of workshops and intensified production. In Phase III (from the 4th century CE onward), with the emergence of Hanseong Baekje and its expansion into surrounding regions, production in the Songjeol-dong area declined, while new centers emerged in the upper Miho River region, particularly around Jincheon. In the Namhan River basin, production activities continued at Chilgeum-dong and further expanded along the main river and its tributaries, eventually forming an iron production base for Baekje. Funerary features such as multiple burials and mortise-and-tenon wooden coffins found near these ironworking sites suggest the presence of groups associated with the Lelang Commandery. These groups likely played a leading role in iron production and were gradually integrated into Mahan society. Earlier interactions with the Jinbeonhan region not only introduced iron artifacts but may also have facilitated the movement of skilled metallurgists. Jinbeonhan-type artifacts, found alongside Lelang-style burial features, support this interpretation. Such intercultural exchanges formed the basis for the development of ironworking facilities in Mahan, likely led by Lelang-affiliated groups from Jinbeonhan who had prior access to advanced metallurgical technologies through contact with the northwestern cultural sphere