Emperor Xian of Han
Cao Cao died on 15 March 220. His son and successor, Cao Pi, soon forced Emperor Xian to abdicate the throne in favour of himself, ending the Han dynasty. Cao Pi established a new state known as Cao Wei (sometimes known inaccurately as the Kingdom of Wei), and he granted Emperor Xian a noble title – Duke of Shanyang (山陽公). The former Emperor Xian died in 234 and was buried with honours befitting an emperor, using Han ceremonies, and the then emperor of Wei, Cao Rui, was one of the mourners. As Emperor Xian's crown prince was already dead, his grandson Liu Kang (劉康) inherited his dukedom, which lasted for 75 more years and two more dukes, Liu Jin (劉瑾) and Liu Qiu (劉秋), until the line was exterminated by invading Xiongnu tribes in about 309, during the Jin dynasty. This practice of an emperor conferring hereditary nobility on his predecessor, from whom he usurped the throne, was known as "er wang san ke" (二王三恪).
Emperor Wu of Han
Emperor Wu is considered one of the greatest emperors in Chinese history, due to his effective governance which made the Han dynasty one of the most powerful nations in the world. Michael Loewe called the reign of Emperor Wu the "high point" of "Modernist" (classically justified Legalist) policies, looking back to "adapt ideas from the pre-Han period." His policies and most trusted advisers were Legalist, favouring adherents of Shang Yang. However, despite establishing an autocratic and centralised state, Emperor Wu adopted the principles of Confucianism as the state philosophy and code of ethics for his empire and started a school to teach future administrators the Confucian classics. These reforms had an enduring effect throughout the existence of imperial China and an enormous influence on neighbouring civilizations.