뉴스레터

Between July 17 and August 17, 2018, the NAHF Research Institute of Ancient-Medieval Korean History successfully participated in the excavation of Balhae's Yeomju Castle in Kraskino, which falls under the Khasansky district of Primorsky Krai, Russia. The project was overseen by myself and the Russian Research Society for Balhae History headed by Professor Evgenia I. Gelman. Below is a review of progress made through this year's excavation and the historical significance of Yeomju castle.

Professor Gelman is an archaeologist well known in Russia for his expertise in the ancient Korean kingdom Balhae. I first met him at the Yeomju Castle site back in 1992 and for the next three decades, I've had the pleasure of remaining friends with Professor Gelman and his Russian colleagues. We have come to have much to discuss about the past, present, and future of our work whenever we meet on site. The recent excavation was carried out in Section 53, which includes a cluster of buildings at the center of the castle. Our main goal was to perform a detailed survey of the foundation of buildings we managed to expose last year and expand our investigation northward. With heightened expectations, we finished preparing for our excavation on the first day we arrived on site and went straight to work the next day after holding a ritual called Gaetoje for the god of land. One week into our survey, we were able to identify a row of three buildings in the section as expected. Three days later, we excavated a Kaiyuan tongbao coin and managed to expose a soil layer. And after twenty years of excavation, we were able to identify a path leading to the temple site as well as the construction method of the inside of the castle wall, which were developments as welcome as rain during a heat wave. The following gives a more detailed introduction to the progress made through the recent excavation.

Newly Discovered Path and the Truth About the Castle Wall

At the 60㎡-large Section 51, further excavation was conducted on the path inside the castle's west side wall. As a result, a new path was discovered below an existing path. The Russians began excavating Section 51 in the 1980s, which includes a temple site close to the castle wall. The temple site is on a hilly area within the northwestern part of the castle, adjacent to the castle's north side wall. Separated from the residential section with a stone wall, the temple was built upon an earthen foundation. This year's excavation newly revealed a four-meter wide path leading directly to the temple from the west gate. The path must have been made before a stone wall was built to section off the temple from the residential area.

The newly discovered path launched an additional survey of the castle wall's foundation. The kingdom of Balhae built the walls of Yeomju Castle by piling stones into two panels and filling the void between them with soil. Yet, how the bottom of the castle wall's inner side was constructed had remained unknown until a path was newly discovered this year. Rather than simply piling the stones up, groundwork was thoroughly done before sand and flat stones were laid like a foundation for stones to be stacked upon it into a wall.

The Central Section of Yeomju Castle

At the central Section 53 of Yeomju Castle, a row of three buildings (Residential site 27, 28, and 29) huddled together was identified through our recent excavation. The size of Residential site 27 is about 6.4 meters long and 4.2 meters wide. Within a ten-by-five-meter excavation zone, the foundation of Residential site 28 has turned out to be 6.5 meters long and 4.1 meters wide. Some of the walls, furnace, and gorae (heat and smoke passage) remain at the site, but excavation needs to be expanded further in order to gain an overall view of the site. As for Residential site 29, traces of an earthen gorae remain. What is worth taking note of is that Section 53 is situated along the main "vermillion bird" boulevard stretching north from the castle's south gate. The fact that the boulevard leads to the foundation under Section 53 can be confirmed both with the naked eye and through photos taken in the air using drones. This indicates that the three buildings discovered in Section 53 must have functioned as a central location in the northern part of the castle.

Uncovered Coin and Soil Layer

Ten days into our recent excavation, a Kaiyuan tongbao (開元通寶) coin was discovered from the bottom of a storage pit in Section 48. The coin was the first to be found in twenty years since Russian experts found one from a well in 1998 while surveying the castle wall. Welcomed with cheers from the excavation team, the newly uncovered coin is 2.4 centimeters in diameter, weighs 3.7 grams, and hints that Yeomju castle had been a site of active international trade.

The Tang dynasty first minted the Kaiyuan tongbao coin in 621. Based on the fact that several coins have been excavated so far from multiple Balhae tombs and considering the patterns on the back side of those coins, they seem to have been minted around the mid eighth century. The coin newly uncovered from a residential area of Yeomju Castle appears to be similar to the one found near the southern wall of the site where Sanggyeong Castle, the largest of Balhae, used to be. The newly uncovered coin may thereby be considered as proof that the use of Kaiyuan tongbao coins could have occurred much earlier than expected, especially since it was found at Dongmosan where Balhae's founder Dae Jo-young established the kingdom as King Go in 698. This idea is also supported by the soil layer in Section 48 that became completely exposed after conducting further excavation around the storage pit where the Kaiyuan tongbao coin was found.

Resource for Studying Balhae and Koguryo's Transportation Routes

Yeomju Castle was an administrative post in Yeomju (鹽州), one of the four provinces overseen by Balhae's eastern capital Donggyeong yongwonbu (東京龍原府). Active exchange took place at the castle with not only central China, but other countries along the western border of China. The castle was also a central point along Balhae's transportation route leading to Silla and Japan. Along its 1.38 kilometer long perimeter, there are three gates to the east, west, and south that have been reinforced with outer works. Since its establishment in 2006, the Northeast Asian History Foundation has continued to conduct joint excavations with Russia, which led to the discovery of various relics and remains over the years. Yeomju Castle has become a landmark among Balhae remains and has settled down as a vital source of research into the history and culture of Balhae as well as Koguryo. And now it has become possible to assume that Yeomju Castle could have served as an exit point to the East Sea for Koguryo. A comprehensive report about the most recent excavation will soon be published, followed by an international academic conference to further discuss the progress made at the castle site and to reconsider the role Balhae played in the history of East Asia.