Ouyang Xun.
Ouyang Xun (557-641), a native of Linxiang, Tanzhou (now Changsha, Hunan) in the early Tang Dynasty, was known as the "Four Great Masters of the Early Tang Dynasty" together with Yu Shinan, Chu Suiliang and Xue Ji, and was also related to the later Yan Zhenqing, Liu Gongquan and Zhao Mengfu are collectively known as the "Four Masters of Regular Script". His regular script is unparalleled in the world for its rigorous standard and sharp writing power. He is known as the first regular script writer in the Tang Dynasty. Both Ouyang Xun and Yu Shinan were famous for their calligraphy in the early Tang Dynasty, and were called Ou Yu. Later generations used their calligraphy to find danger in the ordinary and most convenient for beginners to learn, so they called it Ou style.