Tang Architecture: Modern Science Illuminates Ancient Craftsmanship (II)

Today, we’ll continue to explore modern scientific advances and ongoing research that deepen understanding of Tang-era structures, emphasizing the importance of sustained study and cultural heritage preservation.

Transcript

Rediscovering Tang Architecture: Modern Science Illuminates Ancient Craftsmanship (II)

Today, we’ll continue to explore modern scientific advances and ongoing research that deepen understanding of Tang-era structures, emphasizing the importance of sustained study and cultural heritage preservation.

In the previous podcast, we mentioned that famed architect Liang Sicheng divided ancient Chinese architecture into three stylistic periods: the “bold and vigorous” period of the Tang and Liao, the “harmonious and refined” period of the Song and Yuan, and the “constrained and formal” period of the Ming and Qing.

These transitions, however, didn’t happen abruptly. The influence of Tang architecture lingered well beyond its era. For many years, for example, Tiantai Temple in Changzhi, Shanxi, was thought to be a surviving relic from the Tang.

This ancient temple, hidden on a remote mountain in Changzhi, Shanxi, was discovered during a 1956 cultural relics survey. Its main hall featured dougong, overhanging eaves, and gently sloping roofs – all marked by simplicity, clarity, and structural strength. Coupled with the presence of a Tang-era stele, the building was initially classified as a Tang structure. In 1988, it was even listed as such in the third batch of China’s National Key Cultural Relics Protection Units.

However, because the stele’s inscription was weathered and historical records were lacking, the building’s dating remained a topic of scholarly debate. It wasn’t until a major renovation in 2014 – when the structure was dismantled for restoration – that several ink inscriptions were uncovered, finally solving the mystery. Two of them – “Built in the fourth year of Tiancheng” and “September 2nd, fourth year of Changxing” – clearly dated the construction to the Five Dynasties period, specifically, the early 10th century.

Professor Wang Guixiang of Tsinghua University’s School of Architecture explained: “The artisans in the Five Dynasties may well have been from the late Tang. In the north, under Liao rule, craftsmen likely preserved earlier methods across generations. That’s why Liao architecture still retains traces of Tang style.” In his view, the redating of Tiantai Temple is entirely reasonable – architectural history doesn’t shift as sharply as dynasties do.

He offers another example: the main hall of Hualin Temple in Fuzhou. After extensive research – including document analysis and comparison of proportions and construction methods from the Tang and Song periods – scholars concluded it was likely built in the early Northern Song. Yet it’s not classified as Northern Song architecture. At that time, Fuzhou was still under the control of the Five Dynasties state of Wuyue, so it should be regarded as a Five Dynasties structure.

Wang emphasizes that architectural dating requires multiple lines of evidence, including modern techniques like carbon-14 testing.

This principle echoes what Liang Sicheng and Liu Dunzhen had already articulated back in 1933:

“The dating of a building should primarily be based on the main timber structure, supplemented by documentary records, and cross-verified through elements like ornamentation, carvings, painting, and tile work – only then can conclusions be reliably accurate.”

Around the time Tiantai Temple was discovered, two other genuine Tang-era wooden structures also reemerged in public view: Nanchan Temple and Guangrenwang Temple, both located in Shanxi Province – one in the north, the other in the south.

In 1953, the Shanxi Provincial Cultural Relics Committee heard of an old Buddhist hall in Lijiazhuang, Wutai – less than 50 kilometers from Foguang Temple. A preliminary investigation revealed an inscription on a beam reading: “Repaired on the day of Guiwei during the month of Renshu, third year of the Jianzhong reign of the Great Tang.”

A few months later, six experts conducted a thorough survey. Based on the building’s structure, inscriptions, biographies, and local records, they confirmed the hall dated as the inscription indicated.

This made Nanchan Temple a Tang-era wooden structure built 75 years earlier than Foguang Temple. Although much smaller in scale, it shares many design principles with Foguang, as noted by Zhang Rong, deputy chief engineer at Beijing’s Guowenyan Cultural Heritage Conservation Center.

According to Zhang: The identities, forms, and positions of the principal Buddha and attendant statues in Nanchan Temple match those in Foguang Temple. Even the paired Manjushri and Samantabhadra statues on either side are nearly identical, differing only by one missing attendant bodhisattva on each side.

The Buddha statue in Nanchan Temple stands 1 zhang, 3 chi, and 3 cun (about 4.4 meters), while the main Buddha in Foguang Temple’s East Hall is 1 zhang and 8 chi (around 6 meters). Both are twice the height of a person, aligning with the standards set in the early Tang era Illustrated Sutra of Jetavana Monastery in Shravasti, India.

Most remarkably, both halls follow the same optical proportions: the vertical viewing angle from the forecourt to the hall’s facade and the viewing angle from the entry to the main Buddha inside both follow a 3:5 ratio. This ensures a consistent 31° optimal angle for admiring the structure and the deity from entrance to sanctum.

Thus, while Nanchan Temple may not rival Foguang Temple in grandeur or status, it equally showcases the refinement and precision of Tang-era temple design during the mid- to late-Tang period.

However, time took its toll. Though Nanchan Temple’s main hall survived the Huichang Persecution of Buddhism, it couldn’t withstand centuries of wear and decay. By the 1960s, the structure was in serious disrepair – beams leaning, rafters and purlins rotting, tiles damaged, and brick arches collapsing.

In 1974, under the direction of Qi Yingtao, an ancient architecture protection expert, a comprehensive, year-long restoration was undertaken. Though urgent and necessary, this restoration later became a subject of reflection and debate.

Nanchan Temple had undergone multiple repairs throughout its history, incorporating many later architectural styles. During the dismantling, efforts were made to “restore the original” Tang appearance: doors, windows, and eaves were reverted to Tang designs; roof ornaments like chiwen (mythical fish), xuanyu (suspended fish), and bofeng (wind boards) were recreated based on Foguang Temple, Dunhuang murals, the Bohai Kingdom, and the Song Dynasty Yingzao Fashi. Song-era additions – like camel-back brackets, melon columns, and ornamental supports between ridge beams and purlins – were removed, along with Qing Dynasty colorful paintings on the front eaves and arches. Two Qing-era side halls were demolished, and original foundations such as the platform steps, moon platform, and drainage ditches were restored.

The completed restoration revived Nanchan Temple’s Tang-era style. Yet, in a philosophical sense, it also raised a classic question akin to the Ship of Theseus paradox: if every wooden plank of a ship is replaced, is it still the same ship?

This debate intensified as the conservation principle of “minimal intervention” gained prominence. Qi Yingtao later admitted, “Although we invested much time and effort, the outcome was unsatisfactory. This was a last resort under unavoidable circumstances.”

However, Wang Guixiang believes that the dismantling and restoration of Nanchan Temple’s main hall 50 years ago did not alter its fundamental structure and, by no means, constituted a mistake. He said: “We can’t be certain that the restoration was perfect by today’s standards, but at that time, there were no major issues.” Even Liang Sicheng, who advocated for restoring buildings to their original aged state, cited the Kaiyuan Temple bell tower as an example where reconstructing a Tang-style roof based on surviving bracket sets, eaves structures, murals, and relics was acceptable. Liang said: “Restoration philosophies can evolve; we shouldn’t dismiss earlier work just because our approach has changed. Like Newton’s laws – they’re not wrong, and we still use them, but under different conditions, they may not fully apply.” Wang Xiaolong similarly thinks that although the choices made then had limitations, they were reasonable given the context of the era.

While the restoration of Nanchan Temple’s main hall remains a topic of debate, the renovation of Guangrenwang Temple borders on “disaster.” This Tang-era relic dating to the fifth year of the Dahe reign (831) underwent maintenance in 1958 that neither aimed to restore its original appearance nor preserve its existing state. Rotten rafter ends were simply sawed off, and the wall structures were altered. Due to improper and incomplete construction, the hall later suffered serious issues – leaks, collapses, and cracks – necessitating a complete dismantling again in 2013.

This troubled history mirrors the fate of Guangrenwang Temple itself. Like a frail individual repeatedly subjected to surgery and nearly killed by war, it has gone largely unnoticed except by local villagers and neighbors. Before being included in the fifth batch of National Key Cultural Relics Protection Units in 2001, it was long only recognized at the county and provincial levels. Even as late as 1983, the main hall was still being used as a village classroom, with its murals and sculptures nearly destroyed.

The difficult fate of Guangrenwang Temple does not reflect its true value. Its history is second only to Nanchan Temple and even predates Foguang Temple. As a modest folk shrine dedicated to the Dragon King, it features many distinctly local architectural traits – such as the repeated arch beam braces (gongfang) – which predate similar southern structures by over a century and stand as a rare example in northern China. 

Most importantly, it is the only surviving Tang-era wooden structure devoted to Taoism. This is no coincidence: its location, Ruicheng, is a longstanding Taoist holy site. Lü Dongbin, one of the Eight Immortals and founder of the Danjing (Alchemy) sect, was born here. The nearby Jiufeng Mountains served as his retreat for meditation. During the flourishing of the Quanzhen sect, Qiu Chuji built the magnificent Yongle Palace in nearby Yongle Town to promote Taoism and honor Lü Dongbin. In 1966, this temple complex was relocated just a few hundred meters from Guangrenwang Temple’s site.

Although these “three and a half” surviving Tang structures prove that “there must be Tang constructions among domestic halls,” and enrich the study of traditional Chinese architecture, they remain painfully few compared to the grand Tang Dynasty’s nearly 300-year reign.

Professor Wang Guixiang points out, “Compared with brick and stone buildings, wooden architecture is much harder to preserve – that’s a fact. Wood naturally suffers more from decay; moisture, fire, and southern termites are relentless enemies. Then there are human factors, like wars. Also, Chinese people have a tradition of tearing down and rebuilding every few decades, which is problematic.”

From a rational perspective, Wang believes that any surviving Tang wooden structures are a historic blessing, given how distant that era is and how many threats those buildings faced. By contrast, the richer remains from the Song and Liao periods owe much to a brutal historical event: Whenever dynasties changed, politically significant buildings were destroyed; what usually survived were religious structures. But during Tang Emperor Wuzong’s Buddhist suppression, almost all major temples across the country were destroyed – including Foguang Temple itself.

According to Wang Guixiang, the possibility of discovering additional Tang-era wooden structures beyond the “three and a half” known examples is now extremely slim. However, this does not mean that attention or research should diminish or cease – “there is still much to do, and many questions remain unresolved,” he said.

Many dedicated scholars continue to make persistent efforts. For instance, regarding the main hall doors of Foguang Temple, Liang Sicheng once questioned their original placement. Tang temples typically didn’t require a kneeling space, so the area under the eaves outside the door usually featured a corridor. Later researchers found several clues supporting this: first, the door’s outer column bases formed a complete and well-preserved circle, which Tang craftsmen would unlikely cover with a threshold; second, traces of masonry on the underside of a beam on the hall’s north side indicated possible alteration; third, mortise joints below the inner columns and the entablature showed signs of being filled in.

Since 2015, Zhang Rong and a joint team from Peking University’s Archaeology and Museology School have conducted extensive scientific investigations of the hall. Carbon-14 dating revealed that timber used to fill mortise joints dated to the Yuan Dynasty, suggesting the door was indeed moved during that period.

Carbon-14 technology has enabled further verification or correction of earlier assumptions. For example, a mural on an arch-shaped wall beneath the hall’s ceiling appeared blackened due to oxidation of originally white pigment; Liang believed it to be Tang Dynasty work due to its similarity with Dunhuang murals. Carbon-14 analysis confirmed the straw embedded in the mural’s plaster was from the Tang era, providing high-precision dating.

On the other hand, a monk statue located at the south end of the hall’s outer aisle, once thought by Liang to depict the monk Yuancheng, was shown by carbon dating to contain straw from the Ming Dynasty. Historical records confirm that during the Ming, a monk named Bensui raised funds to restore the dilapidated main hall and Manjushri Hall, adding 296 arhat statues and 245 arhat paintings. Therefore, this statue likely commemorates Bensui, not Yuancheng.

For a long time, research on Foguang Temple relied heavily on data collected by Liang Sicheng and Lin Huiyin decades earlier. Since the 1980s, new surveys have been conducted, and notably in 2005, the Shanxi Provincial Cultural Relics Bureau partnered with Tsinghua University’s Institute of Architecture and Cultural Heritage Conservation to employ 3D scanning and total station technology, improving measurement precision from centimeters to millimeters. This advancement enabled clearer determinations regarding construction materials and architectural proportions.

In 2019, a comprehensive digital survey was carried out jointly by the Shanxi Institute of Ancient Architecture and Mural Conservation, Xinzhou Institute of Cultural Relics and Archaeology, and Zhejiang University. Using extensive imaging and data algorithms, they produced a detailed, full-color 3D model of Foguang Temple – creating a permanent, sustainable archive for its ongoing preservation and presentation. During this process, a previously unknown ink inscription was discovered on a horizontal beam inside the wooden base of the Maitreya statue in the south side chamber of the main hall, reading: “Tang Dynasty Dazhong period, Yanmen craftsman Zhang Shigai.”

Similarly, in 2015, environmental restoration of Guangrenwang Temple began. The temple’s front and surrounding areas were transformed into a new public space, restoring the temple as a spiritual center for villagers and establishing an open-air miniature ancient architecture museum. Wang Hui, an architect from Urban Practice Architecture Studio who led the design, emphasized that only through continuous daily engagement can the temple truly embody the village’s spirit and maintain its authenticity. He also noted that sustainable preservation of a national treasure cannot rely on a remote village alone; it requires specialized heritage presentation methods coupled with tourism development for support.

Although Liang Sicheng’s immediate motivation in searching for Tang architecture was in response to claims made by Japanese scholars, it certainly was not the fundamental reason. Wang Hui said, “His core goal was to build the history of Chinese architecture based on physical evidence. Thanks to Liang Sicheng and others, Chinese architectural history has secured its place in the world’s architectural discourse.”

Today, that immediate motivation has become a thing of the past, but the essential purpose remains unfinished. Building on the foundation laid by predecessors, Wang Guixiang believes that research on Tang architecture – and traditional Chinese architecture as a whole – should continue deeper, more detailed, and broader than ever before.

He said: “In another 100 years, there will still be scholars working on Chinese architectural history. It encompasses economic, technological, artistic, and cultural histories, with many unresolved questions and new discoveries yet to come.”

Well, that’s the end of our podcast. Our theme music is by the famous film score composer Roc Chen. We want to thank our writer Xu Pengyuan, translator Wang Yuyan, and copy editor Pu Ren. And thank you for listening. We hope you enjoyed it, and if you did, please tell a friend so they, too, can understand The Context.