Go to the British Museum, the Metropolitan, or the Musée Guimet today, and you will see tens of thousands of Chinese artefacts.

Bronzes, ceramics, paintings, Buddhist statues, murals — from the Shang and Zhou all the way to the Ming and Qing.

How did they get out?

The answer is not one sentence. It is a hundred years.

In 1840, a British fleet arrived off the Guangdong coast. Two years later, the Treaty of Nanjing forced China to open five treaty ports.

For the next seventy years, China entered a long period of turbulence. War, indemnity, and internal conflict, one after another.

Antiques flowed out in the process.

The outflow was not caused by any one thing. At least three forces drove it.

First, war and looting. The Anglo-French sack of the Old Summer Palace in 1860 and the Eight-Nation Alliance entry into Beijing in 1900 were straightforward plunder. Much of this material went directly into museums and private collections in Britain, France, Germany, and the United States.

Second, indemnity payments. The 450 million taels demanded under the Boxer Protocol were far beyond the Qing government's means. To raise funds, official and princely collections were sold off, often directly to foreign buyers. Some officials also paid debts with artefacts.

Third, museum acquisitions. This is the least discussed but most systematic force. In the early twentieth century, major Western museums established Oriental departments and sent agents to China to buy antiques.

The most famous example is the British explorer Aurel Stein. He entered northwest China three times and removed large quantities of scrolls and silk paintings from the Dunhuang library cave. These are now held mainly in the British Museum and the National Museum of India.

One group played a key role: the antique dealers.

Beijing's Liulichang, Shanghai's Wuma Road, the French Concession in Tianjin — these formed a complete network from acquisition to export.

Dealers bought from declining nobles, bankrupt officials, and tomb raiders, then resold to foreign buyers. Some made fortunes. Others only later realised they had sold not just merchandise.

Some wrote memoirs in old age saying this was the greatest regret of their lives. But once antiques left the country, they rarely came back.

The outflow is a wound in modern Chinese history. But from today's vantage, perhaps we can take a cooler view.

On one hand, the loss to China's cultural heritage is real and enormous. Many top-tier pieces remain abroad and are unlikely to return soon.

On the other, these pieces have become cultural ambassadors abroad. The Chinese galleries of the British Museum and the Met are where many foreigners first encounter Chinese art.

Over the past two decades, the Chinese government and private collectors have been buying back lost artefacts. Some have returned. Many more will remain abroad permanently.

When a collector today buys a Chinese piece on the overseas market, they are in some sense continuing this history.