China's deep-rooted tradition of unity is fundamental to its millennia-old civilization. Spanning over 5,000 years, the history of China tells how various ethnic groups came together to form a diverse but unified nation, as well as a tale of shared efforts to establish, advance and solidify a great homeland. Li Yang, assistant professor at the School of Marxism, Peking University, said Chinese civilization is a civilization of all 56 ethnic groups.