Kublai Khan converted to Tibetan Buddhism for political reasons, but direct control over the plateau was not established until 1621. Political unity was untenable in a rugged land where aristocratic families contested power so closely. Food insecurity also led to incessant raiding warfare in the border region between Szechuan and Kham, a downslope known as Jinchuan, where the locals lived in fortified stone towers called diao 碉.
The engraving above celebrates the subjugation of Jinchuan in 1775. It is one of the “Ten Great Victories” commemorated for the Qianlong court by European artists and produced in Paris and diao are prominent features. Community clusters of these little towers could provide mutual support against siege, while the daunting logistics of the geography deterred foreign invasions. This was a land of rope bridges over swift rapids and narrow cliffside trails, a difficult place to concentrate forces, a wonderful place for an ambush.
To maintain their influence throughout the lands of Tibetan Buddhism, the Mongol court supported the “Yellow Hats” against the three monastic schools collectively known as “Red Hats.” This relationship gave crucial shape to the religion and the culture we now associate with the Himalayan plateau. “Dalai,” a Mongolian word meaning ocean, was first applied to the Tibetan lamas under the suzerainty of Karakorum.
However, this system was in severe decline by the 1740s as a new dynasty in Beijing, the Manchus (Qings), carved out the shape of modern China. Stepping into the vacuum left by the decline of Mongol power, they now supported the so-called “Yellow Hats” in the highlands. This was a divisive move in Jinchuan, where the Red Hats were popular, stirring normally-fractious peoples into a rare unity of effort. A general uprising against the Qianlong emperor began in 1747.
Lasting two years, this became known as the First Jinchuan War, and it was a military disaster for China. One of the commanding generals was executed as a traitor for his failure; the other was allowed the honor of using his father’s sword to take his own life.
One story, perhaps apocryphal, says that during this abysmal first campaign, a company of soldiers lay siege to a single, well-located diao for weeks. Arrows and stones kept them at bay whenever they tried to climb the steep hillsides. Only when they captured a woman trying to draw water one night did they learn that she had been the sole occupant of the tiny fortress that whole time. Joke or not, the anecdote resonates with the embarrassments of the First Jinchuan War.
Undeterred by failure, the Qianlong emperor made a peace, called it a victory, and before the First war was even finished, ordered diao erected for his troops to train on them for the day when his chance would come again.
Gunpowder is a Chinese invention, of course, and cannons were developed simultaneously in Europe and Asia. By the late 17th Century, China also had advanced Portuguese cannon designs to study and they had learned the new iron casting techniques for making gun tubes. Chinese artillery shortcomings in the First Jinchuan War did not result from poor design, then, but training issues — and a logistical contrivance that backfired.
Rather than drag heavy iron cannons for hundreds of miles through difficult mountain country, the Chinese army of 1747-1749 melted down iron ingots and cast their cannons close to the site of operations in a field foundry, or suiying paoju (遂營炮局). Multiple smaller crucibles of melted iron were thus combined into one cast, producing a gun with metallurgical irregularities, so that the tubes exploded, often after firing just a hundred rounds.
Moreover, Chinese gunners did not understand ballistics very well. Diao sited on elevations were difficult to hit with gunpowder cannons unless the battery could be sited at an even higher elevation, which meant dragging heavy guns up a steep hill. The art of indirect fire was a new problem for the Bannermen, and so the Forbidden Palace turned to foreign know-how.
A trade surplus with the world, and the resulting inflow of South American silver, made it possible for the Qianlong emperor to spend nine times as much on the Second Jinchuan War as the First. The problem of feeding and maintaining an army in such country was largely solved by throwing money at it. The Second Jinchuan War was the most expensive conflict China had ever seen, and not by coincidence it was also the last of the Chinese wars of imperial expansion.
The fix for China’s artillery problem was a Jesuit. Félix da Rocha, a Portuguese geodesist, had come to the imperial court as an astronomer. Known by his Chinese name Fu Zuolin, de Rocha’s skills at surveying and mapping the newly-conquered territories of the Qianlong emperor made him one of the highest-ranking foreigners to ever serve the Qing dynasty.

Using diao to experiment with angles of elevation, de Rocha first worked out how to attack the towers of Jinchuan with modern siege artillery and then instructed the Chinese soldiers. “Guns for attacking heaven” — mortars, called xigua pau (西瓜砲) in Chinese — fired “watermelon bombs” at a steep angle that could reach the diao on their craggy foundations, explode, and start fires. Howitzers (榴弹炮) were also effective against the walls of hillside “lamasal castles,” or fortified monasteries.
Advancing through Jinchuan with brutal, methodical discipline, the army of Qianlong ground the defenders down to destruction. A policy of military colonization and immigration incentives then Manchuized the Jinchuan lands. Vengeance has been long, for even today the Jinchuan people are not recognized as a National Minority within China and the region is divided by an administrative boundary.
The age of imperialism was violent, to be sure. Yet in his survey of the second invasion of Jinchuan, War Finance and Logistics in Late Imperial China, historian Ulrich Theobald concludes that the Qing empire “was no less belligerent than the European states in the seventeenth and eighteen centuries.” However, the final campaign of the Ten Great Victories of Qianlong would prove to be the end of Manchu expansion. Policy in Beijing became increasingly closed and xenophobic after Qianlong.
During a wave of anti-Christian oppression before his death in 1781, De Rocha was forced to renounce his vows in order to continue at his high post. Wherever he served Qianlong faithfully, however, de Rocha always asked for the freedom of persecuted Jesuits in exchange, and the emperor was happy to reward his dilligence.
In addition to the European-style copper plate engraving featured at the top of this post, the Qing court commissioned a number of beautful color engravings commemorating the Second Jinchuan War in the contemporary Chinese panoramic style, made by Jesuit hands and produced in France.
This one, The Conquest of Shizheng, has a feature that is strangely rare in siege art: fire. In the detail below, you can see one cluster of diao burning at the center, while a unit of Chinese musketeers suppresses the defenders within another row of towers on the left. The artists have captured the chaos and confusion of a stronghold falling to the storm.
Underlining the finality of the Second Jinchuan War, both for the local people and for China, Qianlong had his soldiers disassemble hundreds of diao towers and bring them to the military parade ground in Beijing, where they were reassembled. Used for training and siege drills, the towers of Jinchuan remained proud trophies of Qing greatness until the bitter end of the dynasty.