The Tubo crown from a tomb in Qinghai Province, has been successfully restored by Chinese archaeologists. Photo: PROVIDED TO CSST

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A crown unearthed from Quangou Tomb No. 1 in Wulan County, Qinghai Province, Northwest China, has been brought back to life through a painstaking restoration effort led by the Key Laboratory of Archaeological Sciences and Cultural Heritage at the Chinese Academy of Social Sciences (CASS). The CASS laboratory for cultural relic conservation has played a central role in numerous “rescue and restoration surgeries” on artifacts from major excavation sites, including the Yinxu Ruins in Anyang, Erlitou in Luoyang, Taosi in Xiangfen, the Haihunhou Tomb in Jiangxi, and the Tusi Tomb in Zunyi, Guizhou.

Excavation of Quangou Tomb No. 1 began in 2018, carried out by a joint archaeological team. This site represents the earliest known Tubo-period [Tubo was a local regime that ruled the Qinghai-Xizang Plateau from the seventh to the ninth centuries] tomb in the Qinghai-Xizang Plateau to feature murals, and it yielded a crown of high scholarly value, discovered sealed within a dark compartment.

Historically, Qinghai has been home to a diverse array of ethnic groups. In 329 CE, the Murong Xianbei, together with other Xianbei and Qiang peoples, established the Tuyuhun regime, one of several regional powers in the northwest. Tuyuhun later submitted to the Tang Empire in the early Tang period and was conquered by the Tubo Kingdom in 663 CE. According to historical accounts, while the Tubo assumed control, elements of the Tuyuhun royal system were preserved. The individual buried in Tomb No. 1 likely held close ties to the royal family, possibly as a member. The tomb reflects both Tang and Tubo influences, shedding new light on the complex dynamics of multi-ethnic interaction in ancient Qinghai.

The crown itself, having endured more than a millennium, was found in a near-shattered state. Its metal structure—less than 200 microns thick, roughly the thickness of three sheets of A4 paper—was severely corroded and would disintegrate with minimal contact. The beaded design of the crown’s front pendant had completely deteriorated, and its original form was no longer recognizable. The textile lining was severely damaged and had lost its structural integrity, posing serious preservation risks. The technical challenges of the restoration were thus immense.

Confronted with the compounded difficulties of “multiple materials, high fragility, and severe corrosion,” the laboratory’s team undertook a restoration study to reassemble the crown’s multi-material components and embarked on a meticulous “cultural relic surgery.” They employed a multi-step process integrating spot welding and laser welding to stabilize the ultra-thin base. In parallel, they developed new methods for the restoration of gold-silver alloys and gilded objects, tailored to the crown’s composite structure.  

Due to centuries of burial, the pearls and beaded tassels that once hung from the crown had scattered like sand. Using non-destructive technologies—including X-ray transmission imaging, flat-panel CT scans, and ultra-depth microscopy—the team conducted thorough research and analysis. During the cleaning process, they succeeded in identifying and preserving the original structure of the beadwork, carefully documenting the arrangement and connections of each bead. In total, 2,582 beads were returned to their original positions—marking the most intricate and extensive beadwork restoration of any scientifically excavated artifact to date.

Following thousands of precision welds, the crown and its beaded pendant were fully restored, revealing their original complexity and elegance. When the crown was finally presented in its complete form, the significance of the painstaking restoration work was revealed: it was nothing short of a technological breakthrough. Using a self-developed, full-process restoration system, the team succeeded in preserving and reconstructing a fragile, multi-material crown from the Tubo period—an unprecedented achievement in Chinese conservation efforts. Notably, the dragon motifs and the beaded pendant of the crown are derived from Central Plains culture, while the standing phoenix and double-lion motifs bear Central Asian influences, corroborating Qinghai’s role as a “highland Silk Road hub” for cultural exchanges. More than a remarkable feat of restoration, the crown vividly embodies the unity in diversity that has long characterized the Chinese nation. It offers tangible, material testimony to the historical process of cultural integration and national identity.

Huang Xi is an assistant research fellow from the Key Laboratory of Archaeological Sciences and Cultural Heritage at the Chinese Academy of Social Sciences.

Edited by REN GUANHONG