All kinds of fonts have their specific generation and popularity times, among which seal script was born in the Spring and Autumn Period and the Warring States Period, and the unified character after the Qin Dynasty destroyed the Six Kingdoms was seal script; Lishu and Xiao Zhuan were almost contemporary, and their main birth period was in the Qin and Western Han Dynasties. The cursive script evolved directly from the official script and was popular throughout the Han and Jin Dynasties. Similarly, regular script was born out of official script and matured in Sui and Tang Dynasties after the development of Wei, Jin, Southern and Northern Dynasties. Running script is between cursive script and regular script, and the running script of Wang Xizhi, a calligrapher in the Eastern Jin Dynasty, is the most typical example.
Therefore, it can be said that regular script and cursive script are "one female brother", but we should seriously discuss that cursive script appeared earlier than regular script.