Ding then had one of the servants take a letter to my great-grandfather in which he wrote: "The rice, salt and silk are not for you, or my son-in-law.

"You should keep them for when there is a famine and they should be given to the poor and the starving.

"The oranges are for my dear daughter who likes them very much and will miss them.

"What is most important, is that the two girls are to serve my daughter as chamber maids and here I want to make it known that your son should never make any of them his concubine."

Although during those days it was customary for men to have concubines, my grandfather obeyed his father-in-law's instructions and remained faithful to his wife.

Eventually, he got one of the girls married to a minor government official and the other to a well-to-do merchant.

The author is professor at Beijing Foreign Studies University.