When Uber swaggered into China a few years ago, it seemed likely to dominate the market, just as it has elsewhere. But the U.S. ride-hailing service collided with Cheng Wei, who merged his smaller alternative with an equally sized local rival to form Didi Chuxing and then used funding from the likes of Apple and Tencent to wage a costly war of attrition with Uber. Didi offered to give away 1 billion yuan worth of free rides, popped up in 400 cities when Uber was just in a few dozen, and invested in U.S. rival Lyft. This summer Uber effectively conceded defeat, selling its China unit to Didi. The company, currently valued at $35 billion, hasn’t expanded outside China, but it now controls the world’s biggest transportation market.