Echoes Across the Himalayas: Harsha and the Tang Dynasty

 

Once, during the Kushana age, a ring of Indo-Iranian and Central Asian control looped around the Himalayas, allowing Buddhist monks, merchants, and ideas to flow freely. The Kushanas ruled from Mathura to Khotan and patronized Gandharan art and Buddhist expansion. They were the hinge between Rome, Parthia, India, and Han China. But by the 4th century, that hinge had rusted.

The Steppe once again gave birth to new horselords. Kingdoms fell, and Kingdoms rose. The ones that stood strong did so because they looked inward in search of stability while fortifying their cores against the battle cries looming on their horizons. The Han Empire was the first to fall, and it didn’t take long before the “Golden Age” of India crumbled under its own might, pushing both behemoths into an era of chaos. 

However, even amidst this vicious cycle of instability, nothing was impossible for those whose visions transcended geographical barriers.

The Pushyabhuti dynasty of India and the Tang Empire of China—neither the largest in their respective eras nor the longest-lasting—shared a moment in the 7th century when distance bent under the weight of intention. And for a brief time, a crescent that mimicked the Kushana carpet of cultural, diplomatic, and spiritual currents arced around the Himalayas, connecting Kannauj to Chang’an.

At the heart of this exchange stood Xuanzang—not a general, nor a king, but a monk. He crossed deserts, mountains, and the wild no-man’s-lands of Central Asia to reach India, where he studied at Nalanda and stood in the court of Emperor Harshavardhana. His Great Tang Records on the Western Regions (Da Tang Xi You Ji) is a treasure trove of topography, polity, and Buddhist life in India. His return to China in 645 was no mere retreat; it was a triumphal reentry, received with state honors. His records shaped the Tang imagination of India as a civilizational peer. Such was the significance of his journey that Xuanzang’s legacy endured far beyond his lifetime, becoming immortalized in China’s cultural memory—most famously through Wu Cheng'en’s Journey to the West and the countless adaptations it inspired.

Harshavardhana and Xuanzang
Image source: Xuanzang (2016), a Sino-Indian co-production.

This was not a one-way admiration. Both emperors sent embassies to each other’s courts. There were six in total, as mentioned in the official court records of the Tang Empire—the Jiu Tang Shu and Xin Tang Shu—each an extension of cultural goodwill and an eagerness to cooperate. Emperor Taizong had much to gain from an ally across the hostile Tibetan plains who spoke his same language of diplomatic outreach, and Harsha, although a conqueror in his own right, was more than happy to reciprocate. This geopolitical necessity is the same incentive that pushed the later Tang emperors to seek allies in Kashmir, but that's a discussion for another time. 

The reverberations of this unlikely brotherhood are evident in the writings of Yijing, another Chinese monk who followed in Xuanzang’s footsteps decades later, sailing to India via the Straits of Malacca and Sumatra. Yijing writes with great enthusiasm about the Buddhist networks that still thrived in the greater Indosphere. He collected over fifty biographies of Chinese monks who traveled to India in his Memoirs of Eminent Monks Who Visited India and Neighboring Regions in Search of the Law During the Great Tang Dynasty. While the Silk Road posed trouble, the Ocean Road glowed brighter. Ports like Tamralipti, Srivijaya, and Nagapattinam carried the faith where no caravan could safely pass.

But this bridge—so vivid in that moment—stood on precarious ground. Territorial integrity and regional ambitions were as important then as they are now. Harsha, for all his reach, never fully subdued the South. His campaigns against Pulakeshin II of the Chalukyas failed. The Deccan remained outside his fold. When Harsha died, an ill-informed Wang Xuance was dispatched as an ambassador to the new Indian regime—only to be attacked en route. According to Chinese records, the Tang response was swift and theatrical. Wang Xuance, with a small force and the backing of Tibetan and Nepalese troops, launched a punitive expedition against the offending Indian ruler, identified as Arunasva, capturing prisoners and statues that were paraded in Chang’an. A bitter end to a relationship that could have reshaped the roof of the world. 

Meanwhile, China too was contending with the Gokturks in the north and the rising threat of the Tibetan Empire in the west. The seemingly immortal Turkic Khaganates were rising like phoenixes—though under different names and with different characteristics—but always with their fangs pointed toward the Great Wall. The later arrival of politically potent Uyghurs and Karluks into the mix would complicate this matter further. The routes that connected Chang’an to Central Asia—and thence to India—were increasingly preyed upon by these entities. They grew stronger with every Tang concession, and they would continue to grow even after the Great Tang’s demise.

However, it was the internal disintegration of imperial values that hastened this process. By the time China faced the An Lushan Rebellion in 755 CE, the Tang dynasty’s grip was fracturing. Internally, its court turned suspicious of foreign faiths. Buddhism, Manichaeism, Zoroastrianism, and Nestorian Christianity—once protected under the Tang umbrella—all faced crackdowns. The same dynasty that once welcomed monks with reverence now watched temples burn in the Great Anti-Buddhist Persecution of the 840s. In India, meanwhile, the fall of Harsha gave way to a hundred kings and the Tripartite struggle between the Palas, Pratiharas, and Rashtrakutas. Each claimed Kannauj. None could rebuild the Pushyabhuti vision. While trade continued to flourish for economical reasons, it was a period of transition marked by the territorial confinement of political outreach in the subcontinent. 

Image source: World History Encyclopedia 

The distant West was not still either. The Abbasid Caliphate rose in 750 CE, toppling the Umayyads and expanding eastward. In 751, at the Battle of Talas, Arab and Chinese armies clashed—not over faith, but over control of Central Asia. The Chinese defeat ensured that Transoxiana would mark the boundaries of their imperial ambition—a geopolitical reality that hasn’t changed even after a millennium. The Umayyads had already landed in Sindh a few decades prior, marking the beginning of Islam’s political presence in India. Thus, between the Arabian expansion and the growing assertiveness of Central Asian Turkic tribes, India and China were pushed into separate worlds. 

Centuries later, it would take the Mongols to redraw the map again—and with it, the rules of connectedness. Their empire reached from the Pacific to the Danube. They ruled both China (as the Yuan dynasty) and much of Central Asia, enabling a kind of restored unity—but not one rooted in shared religion or diplomacy; rather, one enforced by conquest and tributary logic. The four dominions that sprung out of the Great Khan's demise were an anathema of mutual cooperation. Even though Kublai's enthusiasm of knowledge and trade was well-noted in history, none of the Yuan's neighbours could risk an informal subjugation to Beijing, as the echoes of "God's punishment" still trembled the medieval world. 

By then, the world had already changed. The old arc—from India to China through the heart of Asia—had dissolved. What remained were echoes: maritime trade routes, Buddhist texts translated into Chinese, idols carried to Chang’an, and the memory of when a monk’s footprints linked two empires more deeply than any treaty ever could. 

The story of Harsha's kingdom and the Tang dynasty is not just one of diplomacy. It is a story of when the land between empires was not an obstacle, but a bridge. A bridge that crumbled, yes—but not before offering a glimpse of a future that might have been. One still within reach, should we summon the same resolve that once carried the Bhikshus across deserts, empires, and doubt.

For further reading:

1. Harṣa and China: The Six Diplomatic Missions in the Early 7th Century; Zhang Yuan, Chinese Academy of Social Sciences, Beijing

2. The Travel Records of Chinese Pilgrims Faxian, Xuanzang, and Yijing: Sources for Cross-Cultural Encounters Between Ancient India and Ancient China; Tansen Sen

3. India, China and the World; Tansen Sen

4. China’s Cosmopolitan Empire: The Tang Dynasty; Mark Edward Lewis

5. Tang China in Multi-Polar Asia: A History of Diplomacy and War; Wang Zhenping

6. History of Medieval India; Satish Chandra 

7. A History of Ancient and Early Medieval India: From the Stone Age to the 12th Century; Upinder Singh