Emperor Xian was the last emperor of the Han Dynasty in ancient China, reigning from 189 to 220 AD. His reign was marked by political instability and the decline of imperial power, as he was largely a puppet ruler under the influence of powerful warlords and court officials. During his rule, the Han Dynasty faced significant challenges, including internal strife and external threats. Eventually, he was forced to abdicate the throne, leading to the end of the Han Dynasty and the beginning of the Three Kingdoms period, a time of fragmentation and conflict in Chinese history.