It was unfortunate but I had to be in Causeway Bay when the Hong Kong Sevens was on. After weaving my way past inebriated men and women making a nuisance of themselves in the MTR station, I found myself blocked at the exit by ticket scalpers. Most of them were of European descent.

Considering a mainland child having a snack on the MTR triggered a shouting match between locals and "locusts" last year, it's curious to witness the sheer amount of latitude Chinese Hongkongers allow white people, even where illegal scalping is involved. I don't blame the Europeans in Hong Kong at all - they shouldn't be responsible for how the natives think and behave.

When China was part of the Mongol Empire, the foreign rulers imposed on it a caste system largely based on race. At the top, of course, were the Mongols, followed by the Semuren, which could mean "people with coloured eyes" or "people of various categories". These Semuren were from Central Asia, the Middle East and Europe, and were favoured by the Mongols as administrators of the empire. Many of them settled in China and became powerful officials and wealthy merchants.

Next in line were the Han people, mostly Han Chinese in the north but also the Khitan, Jurchen and Koreans.

The lowest caste were the Nanman, "southern barbarians" of the former Southern Song dynasty, who were the last to be conquered.