I think the word “enslavement” might be the wrong term.
In the 1600s, the Manchus were instrumental in causing the collapse of the Ming dynasty. Eventually, they came to control all of China and established the Qing dynasty. During the period in which the Manchus were consolidating their control and suppressing various groups still loyal to the Ming, they imposed the requirement that all of their subjects (both Manchu and Han Chinese) wear the traditional Manchu hairstyle–the queue–as a symbol of loyalty to the Qing emperor. There’s a short outline of the Qing dynasty at http://www.bartleby.com/67/852.html.
In this context, I wouldn’t use the word “enslavement”–it certainly wasn’t just slaves that had to wear the queue. And the ethinic Manchus even wore it proudly. On the other hand, I’m sure that Ming loyalists at that time would have agreed with Dex’s usage. To them, the imposition of foreign Manchu rule was certainly a political “enslavement”. They were fighting a desperate rearguard action to put a Han Chinese emperor back on the throne.
For another interesting perspective on the meaning of the queue much later in history, take a look at this site: http://www.yorku.ca/iwai/kevinn.html
Thanks for the addition, Chu. Yes, I certainly meant “enslavement” as “political enslavement.” I’ll edit the report to make that clear. I tend to have a negative reaction to statements by an emperor that “all subjects must…” So I guess my political orientation was showing.