Ruzi Ying
Ruzi Ying (; 5 – 25), also known as Emperor Ruzi of Han and the personal name of Liu Ying (劉嬰), was the last emperor of the Chinese Western Han Dynasty from 6 CE to 9 CE. After Emperor Ai of Han and Emperor Ping died without heirs, Wang Mang chose the youngest of the available successors in order to maintain his power in the government. The child Ying was soon deposed by Wang Mang who declared the Xin Dynasty in place of the Han. During Xin Dynasty, Ying was under effective house arrest—so much so that as an adult, he did not even know the names of common animals. Before and after the Xin Dynasty was overthrown in 23 CE, many ambitious people claimed to be restoring the Han dynasty. In 25 CE, a rebellion against the temporary Gengshi Emperor used the former Emperor Ruzi as a focus, and when the rebellion was defeated, he was killed. He is often viewed as an innocent child who was the victim of tragic circumstances. (The expression "Emperor Ruzi" is a misnomer, as he never assumed the throne and was only named crown prince. Nevertheless, he is commonly referred to as such.)
Science and technology of the Han dynasty
The Han dynasty (206 BCE – 220 CE) of ancient China, divided between the eras of Western Han (206 BCE – 9 CE, when the capital was at Chang'an), Xin dynasty of Wang Mang (r. AD 9–23), and Eastern Han (25–220 CE, when the capital was at Luoyang, and after 196 CE at Xuchang), witnessed some of the most significant advancements in premodern Chinese science and technology.