Beginning in the late Han Dynasty.
Regular script is also called Zhengkai, Zhenshu, and Zhengshu. It gradually evolved from the official script founded by Cheng Miao, becoming more simplified, horizontal and vertical. "Cihai" explains that it "has a square shape and straight strokes, which can be used as a model." Hence the name regular script. It began in the late Han Dynasty and has been popular to modern times.
The history of the development of Chinese regular script is divided into four periods: the embryonic period of regular script - Qin and Han Dynasty, the development period of regular script - Wei, Jin, Southern and Northern Dynasties, the prosperous period of regular script - Sui, Tang and Five Dynasties. The period of longevity - Song, Yuan, Ming and Qing.
Extended information
Four famous masters of regular script:
Ouyang Xun was born in the first year of Yongding (557) of Emperor Chenwu of the Southern Dynasty. He is famous for his regular script and running script. He is the largest regular calligrapher in the history of calligraphy, and his font is called "European style".
Yan Zhenqing's calligraphy can be divided into early and late stages. It was only after the age of 50 that he developed a strong and vigorous style. His large-character regular script is particularly strong and vigorous, with an "arrogant and inviolable look", and the quality of his calligraphy is quite consistent with his character.
Liu Gongquan lived in the thirteenth year of Dali of Tang Dynasty - the sixth year of Xiantong, the sixth year of Emperor Yizong of Tang Dynasty, and he was 88 years old. Originally from Jing Zhaohua. From the palace to the crown prince's young master, he was called "Liu Shaoshi" in his old life. He first studied Wang Xizhi and studied the brushwork of Ouyang Xun and Yan Zhenqing, and then became his own style. The regular script he writes is vigorous and charming, with strong bones and strong morals. Compared with the Yan body, the Liu character is slightly thinner, so it is called "Yan Jin Liu Gu".
Zhao Mengfu (1254-1322), also known as Ziang, also known as Xuesong Taoist and Crystal Palace Taoist, was born in Huzhou (Wuxing, Zhejiang). When he reached the Imperial Academy, he accepted the imperial edict and was awarded the title of Doctor. He was granted the title of Duke of Wei and was given the posthumous title of Wenmin. He is the author of "Songxue Zhaiji". Zhao Mengfu was an influential calligrapher in the early Yuan Dynasty.
Baidu Encyclopedia - Regular Script
Baidu Encyclopedia - Four Masters of Regular Script