The Emergence and Development of Lead Glaze and Lead Glass during the Three Kingdoms to Unified Silla Periods

This paper examines the emergence and development of lead-glazed and lead-glass artifacts from the Three Kingdoms to the Unified Silla period by dividing their technological evolution into three stages. In Baekje, the use of lead glaze and lead glass began in the late 6th century, with Stages 1–3 were seemingly introduced almost simultaneously. Although no scientifically analyzed examples exist for Stages 1 and 2, a Chinese lead-glazed inkstone represents Stage 1. A lead-glass fragment excavated from the workshop beneath the site of the Lecture Hall at Iksan Wanggung-ri belongs to Stage 3 and is thought to have been produced using lead ore from Zone 4 of the Southern Korean Peninsula. The adoption of both artifacts and production technology is attributed to Baekje’s active exchanges with Northern Qi. In the early 7th century, lead-glazed and lead-glass artifacts increased dramatically, with Zone 4 of the Southern Korean Peninsula serving as the main source. Lead glaze typically comprised a base material, flux, stabilizer, and colorant (Fe2O3), while lead glass was characterized mainly by the base material and flux, forming two types. In Silla and Unified Silla, the development of lead glaze and lead glass progressed gradually through Stages 1 to 3. Stage 1, assigned to the late 6th century, is poorly represented archaeologically. Stage 2, corresponding to the early 7th century, is marked by the application of lead glaze to late Silla-style pottery. Stage 3 began in the late 7th century, using lead ore primarily from Zone 2 of the Southern Korean Peninsula. Lead glaze consisted of a base material, flux, stabilizer, and colorants such as Fe2O3 and CuO, while lead glass was composed mainly of the base material and flux, and can be divided into three types. Silla appears to have adopted Baekje’s lead-glass technology, replacing the earlier leadglazed floor tiles with highly glossy and transparent lead-glass tiles. These findings suggest that while pre-unification Silla mainly developed lead-glazed artifacts under Chinese influence, post-unification Silla advanced its technology by incorporating Baekje traditions.