Who was the first calligrapher in Tang Dynasty?

The four masters of regular script are the collective names of four calligraphers who are famous for regular script in the history of calligraphy. Regular script, also known as Four Books, has four styles in Yuan Dynasty: European style, Yan Zhenqing style, Liu Gongquan style and Zhao Mengfu style. Ou Yangxun (557-64 1) was born in Linxiang, Tanzhou (now Changsha, Hunan). His calligraphy achievements are based on regular script, with bold brushwork and unique structure, which is called "European style" by later generations. Ou Yangxun in Tang Dynasty (European Style): Regular script is rigorous and bold, and it is known as "the first regular script in Tang Dynasty", and its masterpiece is "The Ritual Spring of Jiucheng Palace".