The Hong Kong families that dominate nearly every facet of economic life in China's richest city are not well known abroad, with a few exceptions such as Li Ka-shing, by dint of his global ports and mobile phone empire, and Stanley Ho, the gambling tycoon.

Yet these families control immense fortunes and, for a territory of just 7m people, occupy a disproportionate number of slots on global rich lists. In February, even with the valuations of their companies headed for a six-year low, Forbes magazine estimated that the fortunes of Hong Kong's 10 richest families at $58.7bn. As their empires expand into China and swell in tandem with the country's fast-growing economy, relative global anonymity will be harder to maintain.

The family of Cheng Yu-tung, the city's sixth-richest with an estimated net worth of $3.8bn, is a typical example. Its history reflects the development and workings of Hong Kong's economy, and also the unprecedented opportunities un-folding on the Chinese mainland.