Zhao says he was heartbroken after reading about the incident. "They sold women for money, bought them for their fertility to keep the clan going, and women showed absolute obedience to men's lust."

The death of Zhang also encapsulates women's status in the Qing Dynasty (1644-1911). Despite laws that forbade forced marriages or the sale of women, the lease or sale of women widely happened, especially among the poor, Zhao says.

He cites research by Matthew H.Sommer of Stanford University, in California, the United States, which shows a similarity between the transaction of women and land in ancient China. Even the same terms and definitions were used in trading contracts. More pathetically, Zhao says he found "many women were voluntarily, or knowingly involved in these transactions, just like the victim in this case. If Zhang didn't change her mind after being sold to the second husband, I think this 'deal' would not have left any trace for us to find".

He says he found records of suicides among women during the Qing Dynasty, a majority of which had to do with a woman's determination or need to preserve her chastity after her husband's death. Such suicides were "honored" by the imperial court, which encouraged more women to do the same.

"With few opportunities for an education or a career, women hardly had channels to achieve anything on their own. Being 'honored' for their chastity could at least get their families dozens of silver ingots, and more benefits could follow," he says. "Eventually the social custom developed that emphasized chastity while neglecting life."