Chang'an

http://en.wikipedia.org/wiki/Chang%27an

"Chang'an is an ancient capital of more than ten dynasties in Chinese history. Chang'an literally means "Perpetual Peace" in Classical Chinese. During the short-lived Xin Dynasty, the city was renamed "Constant Peace" (常安, pronounced the same way in Mandarin Chinese); yet after its fall in the year 23 AD, the old name was restored. By the time of the Ming Dynasty, the name was again changed to Xi'an, meaning "Western Peace", which has remained its name to the present day."