The Legacy of the Koguryo Kingdom

The enigmatic Koguryo kingdom flourished in Northeast Asia from the 1^st century BCE until the 7^th century CE. A true regional power that kept the relentless forces of its neighbors at bay for over 700 years, the kingdom’s territory at its peak ranged from the middle portion of the Korean peninsula in the south, the edges of the Primorsky region in present-day Russia in the east, and the Songhua and Liao rivers in present-day China in the north and west, respectively.

The legacy of the Koguryo culture has fortunately not been lost to history as innumerable tombs have been found throughout the kingdom’s former domain—over 10,000 discovered to date, the most impressive of which are believed to be the resting places of Koguryo kings and their families, as well as members of the aristocracy. So far, a number of these tombs have gifted present and future generations of humanity with a glimpse into the intricacies of the daily lives of Koguryo royalty. This is because the walls of around 100 tombs, over 70 within the Democratic People’s Republic of Korea (DPRK), are adorned with elaborate mural paintings depicting the ruling class in portraiture, in the middle of performing various duties, or in an assortment of interplay situations with others. These detailed portrayals reveal the culture’s firm belief in an afterlife that is not different from earthly life, with the many rituals and riches artfully rendered on the tomb walls ensuring a comfortable reign long after death. The evolution of Koguryo artistry is also brought to light with the variation of painting styles, patterns, and subjects on display in every mural, allowing even more insights into the development of the culture as a whole.

The Development of Tomb Design 

Based on the type of design and method of construction, the Koguryo tombs discovered thus far are classified as belonging to one of four distinct periods. The oldest tombs date back to the Early Period, from the 1^st to the 3^rd century CE. Most tombs built during this time consist of a single subterranean chamber into which the deceased’s casket was lowered, with the access point subsequently sealed by a pyramid-shaped pile of stones. Such stone pile tombs have no entrances and are generally found beside rivers and streams. Although not as widespread, semi-submerged single-chamber tombs made of stone were also built during this time. Such stone chamber tombs have frontal entry points usually facing west or southwest, with the chamber portions above ground purposely covered with soil to form pyramidal mounds. Tombs constructed during the Early Period typically had simple flat ceilings and walls without adornments or mural paintings.

Stone chamber tombs covered by earthen mounds became predominant during the First Middle Period, from the 3^rd to the mid-4^th century CE. Tomb layouts eventually included niches and anterooms, while the first mural paintings showing the tomb occupant in portraits as well as daily life scenes—genre paintings—began to adorn chamber walls. Mural paintings of abstract patterns also started to become common at this time, to go along with vaulted and corbelled ceilings. The addition of a second burial chamber characterized the stone-chamber tombs of the Second Middle Period, from the mid 4^th to the 6^th century CE. Together with portraits, genre paintings, and abstract patterns, tomb walls during this period included depictions of the Koguryo culture’s guardian deities—mythical animals representing the four points of the compass believed to have the power to repel demons. Ceiling construction became more elaborate as well, as evidenced by the more prevalent use of the laternendecke style.

During the Later Period, from the 6^th to the 7^th century CE, all tomb construction was of the stone chamber type covered by earthen mounds, with all entrances oriented to the south and all ceilings in the laternendecke style. The distinction of the tombs of this final era of the Koguryo kingdom is the presence of a chamber adorned solely with mural paintings of the guardian deities. So influential were all these approaches to tomb design, developed from the Early Period all the way to the Later Period, that neighboring kingdoms in the Korean peninsula all the way to the islands of Japan eventually constructed their tombs in a similar fashion.  

Cooperation between UNESCO and the Republic of Korea

In recognition of the importance of the Koguryo culture’s legacy and to ensure that it continues to be passed on to succeeding generations for all the world to appreciate, UNESCO has been working closely with the DPRK to protect and conserve the Koguryo kingdom’s tombs and mural paintings. Since the 1980s, UNESCO has been fielding mural painting experts to the various tomb sites as well as providing the DPRK with both technical and financial assistance for its conservation program. Upon the DPRK’s ratification of the World Heritage Convention in 1998, cooperative efforts between UNESCO and the DPRK to preserve the tombs and mural paintings increased further, eventually leading to the involvement of South Korea with the launch of the UNESCO/Republic of Korea Funds-in-Trust project “Preservation of Cultural Heritage in the People’s Democratic Republic of Korea, Notably the Yaksu-ri Tomb“ in 2001.

In 2004, the “Complex of Koguryo Tombs” was successfully inscribed as the DPRK’s first UNESCO World Heritage site. Although this certainly marks a major milestone that rightfully places the site in a position of global prominence, UNESCO the DPRK, and the Republic of Korea (ROK) together continue the worthwhile endeavor of preserving the Koguryo tombs and its mural paintings.

The UNESCO/Republic of Korea Funds-in-Trust project “Preservation of Cultural Heritage in the People’s Democratic Republic of Korea, Notably the Yaksu-ri Tomb” was made possible by a US$100,000 fund allocation from the ROK. Discovered in 1958 in the area of South Pyongan Province just southwest of Pyongyang, Yaksu-ri tomb contains a second chamber lined with niches as well as exquisite mural paintings with subjects prevalent in both the Middle and Late Periods—a fitting representation of how tomb designs and mural painting styles evolved in Koguryo culture. Given that it was in urgent need of preservation, Yaksu-ri tomb was deemed an appropriate starting point for the first phase of the joint conservation efforts.

Initial Assessment Mission

In November of 2001, UNESCO fielded a mission to the tomb to ascertain the most appropriate protection methods against water infiltration and humidity, the two most urgent threats to the site. Comprised of experts in moisture control and humidity, as well as a mural painting conservation, the mission was able to assess the state of conservation of the tomb and its mural paintings, as well as determine that increased moisture and inundation from rising ground water were likely to affect the tomb as a result of on-going construction at a reservoir near the premises—a timely discovery that very well averted further damage. Sample pigments were extracted from the mural paintings for chemical analysis and the tomb was also equipped with a hygrometer and rain gauge to allow constant monitoring of interior moisture conditions.

Detailed Data Gathering Missions

UNESCO subsequently endeavored to make certain that the most effective approach to safeguarding Yaksu-ri tomb was employed. For this purpose, two technical missions to the site were then carried out to collect the accurate ground water readings and precise topographic measurements required. In October of 2002, the first of these technical missions equipped the tomb with piezometers to measure ground water levels and also instructed the DPRK personnel in charge of the tomb how to operate the equipment (these piezometers continue to provide readings crucial to the proper monitoring of the tomb). This undertaking was conducted together with a UNESCO Secretariat delegation to the site the task of which was to negotiate with DPRK authorities the general terms and implementation modalities of the project’s second phase. In December of 2002, the second technical mission was dispatched to take detailed measurements of the site in order to produce a topographic map to the scale of 1:1000 meters.

 Findings from the first phase of the project eventually led UNESCO to formulate an overall strategy that involved implementing systematic and scientific research and conservation techniques for all of the Koguryo tombs and mural paintings to be protected, as well as increasing the capacity of the DPRK’s experts and government authorities in safeguarding their country’s cultural heritage sites.

Launched in 2003 with a fund allocation of US$500,590, the second phase of the UNESCO/Republic of Korea Funds-in-Trust project was entitled “Preservation of Cultural Heritage in the People’s Democratic Republic of Korea, Notably the Yaksu-ri Tomb, Phase II, and Capacity Building at the Korean Cultural Preservation Center” as it incorporated developing the DPRK’s ability to preserve its cultural heritage sites on a national level.

Structural, Micro-Climate, and Mural Painting Investigations

More conservation measures were implemented at Yaksu-ri tomb, including extensive scientific investigations and geophysical surveys conducted between 2004 and 2006 to ascertain the structural issues endangering the site. The information yielded during these technical missions also led to a definitive understanding of the correlation between rainfall, reservoir levels, the underground water table, and the stratigraphy of the area—the crucial basis for all subsequent measures to successfully prevent water infiltration.

Structural assessments and micro-climate testing were also carried out during these missions at the other tombs comprising the Complex of Koguryo Tombs World Heritage property, particularly Anak III, Susan-ri, Tokhung-ri, Jinpa-ri I, as well as Kango I, II, and III. Structural issues requiring immediate attention were discovered at Anak III Tomb, prompting the installation of a crack gauge at its ceiling for further monitoring.

Over the same three-year time period, technical missions also extracted pigment samples from the mural paintings in the aforementioned tombs for analysis, eventually confirming that the fresco technique was the predominant style utilized—a significant revelation given that this method was previously considered to be unknown to the region. The results of the analysis showed that portions of the mural paintings in Yaksu-ri and Susan-ri tombs required emergency stabilization measures, and also pointed to the methods best suited for their restoration.

Establishment of Laboratory and Library

As the DPRK’s Korean Cultural Preservation Centre (KCPC; the DPRK government agency overseeing heritage conservation efforts) did not at the time have a laboratory with equipment necessary for the proper preservation of the mural paintings, a diagnostic laboratory unit was provided in 2004 by UNESCO (in cooperation with ICCROM) as part of the project’s second phase. With the laboratory in place, detailed chemical and biological analyses of samples from the tombs could be undertaken within the DPRK—eliminating the costly process of transporting samples to other countries. In addition to the laboratory, a library containing up-to-date conservation and restoration publications provided by ICCROM was set up at the KCPC to benefit the DPRK’s conservation community.     

Mural Painting Conservation Workshops

To build the DPRK’s capacity to conserve the mural paintings, UNESCO developed a three-year training program for the local experts tasked with the preservation and restoration efforts. The initial workshop in 2004 focused on basic conservation principles, relevant case studies, and developing teamwork; the second workshop in 2005 tackled humidity and structural issues, and also incorporated on-site training at the tombs; while the third workshop in 2006 concentrated on paint sample analysis and other laboratory processes. The workshops also led to the creation of a National Conservation Team composed of the DPRK’s experts from various disciplines involved in the project.  

Susan-ri tomb in particular, discovered to be in need of emergency stabilization, was a noteworthy case for on-site training as DPRK conservators were trained on the spot while UNESCO experts executed the actual work. Overall, the training workshops involved proper documentation of the work through photography, research into possible causes for the cavities within the mural paintings, accurate monitoring of the tomb’s micro-climate, as well as chemical analyses of the pigments and biological analyses of microorganisms found in the tombs.

During the final workshop in 2006, the mural paintings in the tomb of King Won Gun were also found to be in urgent need of repair. Significant portions of the mural painting’s renders were detached from the walls prompting UNESCO and DPRK experts to carry out the necessary emergency work.

International Symposium on the Koguryo Tombs

To compliment the three-year training program for DPRK experts, an international symposium entitled “Conservation of the Koguryo Tombs and Mural Paintings – Introduction of a Scientific and Methodological Approach” sponsored by the Cultural Properties Administration of the ROK was conducted in Seoul in October 2004. The symposium brought together tomb and wall painting experts from all over the world for an in-depth discussion of the Koguryo tombs and how best to preserve them. The event afforded conservators from the DPRK an extended opportunity to compare notes and learn from the field’s top experts, as well as become part of the international network of conservation professionals formed during the symposium.

The third phase of the UNESCO/Republic of Korea Funds-in-Trust project, entitled “Preservation of the Koguryo Tombs and Mural Paintings in the Democratic People’s Republic of Korea,”  launched with a fund allocation of US$1,000,312, brought the joint conservation efforts to a new level. Whereas the first two phases focused on a comprehensive scientific and methodical conservation approach to the tombs and mural paintings (starting with the Yaksu-ri tomb), as well as building the national capacity of the DPRK in preserving its cultural heritage sites, UNESCO and the DPRK’s National Conservation Team (NCT) opted to undertake a flagship project for phase three involving the full-scale conservation and restoration of Susan-ri tomb and its mural paintings.

From the operational start of the third phase of the project in April 2008 onwards, field activities have been carried out three-four months a year (in the spring and in the autumn), in close collaboration with the international UNESCO experts and the national team. The works undertaken at the Susan-ri tomb, which was deteriorating rapidly at the beginning of this project, became a model for on-site training, under the leadership of UNESCO’s conservation expert, Rodolfo Luján.

The main objectives for this phase were the conservation of the mural paintings in the Susan-ri Tomb, designated as a pilot project, and structural interventions both for the Susan-ri and Yaksu-ri Tombs. The project also aimed to reinforce national capacities through on-site training and by organising a Study Tour for selected members of the DPRK National Conservation Team, while research activities focused on methods for the removal of mud encrustations on the mural paintings and the monitoring of microclimate environments of the Koguryo Tombs, in order to establish a long-term preservation strategy for the Koguryo heritage site.

Upon completion of the activities, Phase III of the project achieved the following tangible outcomes:

• Conservation: Completion of the conservation of the Susan-ri Tomb’s mural paintings, as well as the tomb’s structural problems, such as serious water infiltration both for the Susan-ri and the Yaksu-ri Tombs, under the guidance of international experts, notably Rodolfo Luján, Sandro Massa and Claudio Margottini;
• Research: Completion of various research projects in collaboration with the Rathgen Research Laboratory of the Berlin State Museums, Korean mural painting conservator Mr Kwon Woong Lim, and international experts working with UNESCO. These were intended not only to carry out scientific research for conservation, but also to establish a learning process about the conservation methodology, including its application for the DPRK National Conservation Team;
• Reinforcement of the DPRK national capacity: Reinforcement of the DPRK national capacity in conservation and management of the Complex of the Koguryo Heritage through a series of operational works including the Study Tour Programme, which were designed to foster insight and ensure conservation in keeping with international standards;
• Provision of equipment/materials: Provided both basic infrastructure and technical and specialized equipment required for conservation (via Maccaferri Asia and GlasBau Hahn), continuing training and human resource building for DPRK national experts through on-site training; also provided the project vehicle (mini-bus); The newly provided glass barrier through glas Bau Hahn considerably reinforced the presentation of the Susan ri Tomb’ s mural painting
• Promotion of the Koguryo Tombs and mural paintings: Successful promotion of the Koguryo World Heritage and the work of UNESCO, at the international level through various promotional activities such as the exhibition organized at the UNESCO Headquarters in 2012.

The activities implemented in the framework of this project reinforced the national capacities in the field of conservation and management, which is one of the primary concerns in ensuring the sustainability of the Koguryo World Heritage site of the DPRK. The project also benefited directly the local experts, who had the opportunity to strengthen their theoretical and operational knowledge, which will in time allow them to independently lead restoration works and thereby guarantee the long-term conservation of the property. It also allowed the National Conservation Team to work in conformity with the highest international standards, particularly the ICOMOS Principles for the Preservation and Conservation-Restoration of Wall Paintings (2003), when performing all structural interventions, scientific analyses, and mural painting restorations.

Finally, as a result of the project, a set of guidelines and recommendations for the conservation of mural paintings, particularly in damp and/or subterranean environments, was formalised at the Experts Workshop at the Museum für Asiatische Kunst Berlin, on 2-4 June 2015.

Berlin Guidelines

Promotional Brochure on the Koguryo Kingdom and its Legacy

In 2005, as part of the second phase of the project, UNESCO published a comprehensive brochure about the Koguryo tombs and its mural paintings entitled Preservation of the Koguryo Kingdom Tombs. The publication contained detailed information on the Koguryo kingdom’s history, the evolution its tomb designs, the development of its art through mural painting styles and subjects, the astronomical basis and spiritual meanings of the tomb drawings, the background of the excavations, as well as the details of the conservation work undertaken—all printed in high quality color and with accompanying photographs and diagrams.

During the General Conference of UNESCO in 2005, the DPRK delegation gave each Member State a copy of the brochure in order to raise international awareness of the cooperative conservation efforts involving the two Koreas and UNESCO. A further 200 copies of the brochure were shipped to Pyongyang for distribution to concerned government agencies and the conservation community of the DPRK. An additional 200 copies were also sent to various universities and institutions throughout Europe and North America involved in the study of Korean culture.

Photo Exhibition at UNESCO

In October of 2012, an elaborate exhibition on the Koguryo tombs and mural paintings was mounted at the headquarters of UNESCO in Paris. The 16-day exhibit featured replicas of the tomb gateways and walls to afford visitors a realistic view of the tomb interiors, as well as to showcase the magnificence of the mural paintings therein. Also on display were photographs of the actual tombs and mural paintings, complete with in-depth explanations of the various genre paintings depicting Koguryo life. Exhibited as well were 80 photographs documenting the joint conservation efforts carried out under the different phases of the UNESCO/Republic of Korea Funds-in Trust project, all arranged in chronological order to provide a timeline of the many aspects involved in such a complex undertaking. With the welcoming remarks of the opening ceremonies delivered by UNESCO Director-General Irina Bokova, the well attended exhibit successfully commemorated the unprecedented cooperation between the DPRK and the ROK on a revolutionary conservation project benefitting a common Korean culture.