China is unique among the world’s most populous nations in that it considers itself ethnically near-homogenous, Martin Jacques writes in an essay at the BBC News Magazine. “[M]ore than nine out of 10 Chinese people think of themselves as belonging to just one race, the Han,” he says. But it wasn’t always so. As Jacques explains, the history of ethnicity in China is far more complicated than this suggests, with lessons for both how that makes China unique and what it means for the country today.

The history of China, he suggests, is in some ways a story about ethnicity.

How did China evolve? It is essentially the story of the Han and the way in which over a period of two millennia they came to absorb the great majority of other ethnic groups.

Before the victory of the Qin dynasty in 221 BC, China was divided into many different states. The process of its subsequent unification was the creation of an empire. But whereas all the other great empires of the world have long since broken up, China remains united. Why? In one word — the Han. The Han identity has served as the glue which has kept a geographically and demographically vast country together. Without that shared identity, China would long ago have fallen apart.

Jacques argues that this ancient history of Han unification informs some of China’s greatest strengths and weaknesses up through today:

If the strength of the Han identity is that it has held China together, its weakness, I would argue, has been its relative lack of respect for difference, an underlying assumption that the non-Han should become like the Han — indeed eventually be absorbed into the Han. This attitude is not difficult to understand, it is how the Han became almost, but not quite, synonymous with being Chinese, or, to put it another way, how China was created.

Jacques explores these implications for China’s remarkable stability and success, its relations with the West and its still-troubled hold over non-Han peoples such as Tibetans. As with any history that views something very complicated through a single lens, there are shortcomings to this ethnic history. But it does offer some fascinating insights into how China sees itself, its place in the world, and the rest of the globe’s inhabitants.

For a view of China’s diversity, check out these amazing “family portrait” photos of 56 of China’s largest ethnic groups.

– Max Fisher