"Pian Zhang Zuisu" is the collective name for Zhang Xu and Huai Su, two cursive calligraphers in the Tang Dynasty. Since cursive writing began to take shape in the Han Dynasty, it entered a glorious stage in the Tang Dynasty. There were a large number of calligraphers who practiced cursive calligraphy. Among them, the one with the highest achievement and far-reaching influence was "Dian Zhang Zui Su".
Zhang Xu, courtesy name Bogao, was born in Wu (now Suzhou). His birth and death dates are unknown. He was probably active during the Kaiyuan and Tianbao years of the Tang Dynasty. Official Jinwu has a long history, and he is known as "Zhang Changshi". Zhang Xu is most famous for his Kuangcao calligraphy, but he studied regular script seriously and has left behind a regular script tablet rubbing of "Lang Guan Shi Ji". The exquisiteness of regular script laid the foundation for the formation of Zhang Xu's Kuangcao calligraphy. Among the cursive writers in the Tang Dynasty, Zhang Xu was the first to write a new style. His cursive calligraphy was praised by Han Yu, a writer in the late Tang Dynasty, as: "happiness and anger, embarrassment, sorrow, joy, resentment, yearning, and intoxication." Boredom, injustice, something that moves the heart, must be expressed in cursive calligraphy. "Zhang Xu's cursive calligraphy melts his mood into the words. The strokes of his writing are strange, continuous, ups and downs, high-spirited, and full of twists and turns. , echoing in between. Zhang Xu's wild grass, Li Bai's poetry, and Pei Min's sword dance were known as the "Three Wonders" in the Tang Dynasty. Zhang Xu once taught calligraphy to Yan Zhenqing. Yan Zhenqing commented on Zhang Xu's cursive calligraphy that "Zhang Changshi's posture and temperament are epileptic, surpassing ancient and modern times." Therefore, he was called "Zhang Epilepsy".
Huai Su was another famous cursive calligrapher in the Tang Dynasty after Zhang Xu. He was from Hunan. He became a monk when he was young and loved calligraphy since he was a child. Huai Su studied calligraphy assiduously. Later, in order to improve his calligraphy, he left Hunan and went to Luoyang, Henan and Xi'an, Shaanxi to seek teachers and friends. Huaisu likes to drink, and after drinking he gets excited and starts writing. His words are like a sudden rain and whirlwind, flying and turning, with many changes, without losing his writing skills. Xu Yao, a person at that time, after viewing Huai Su's wild cursive works, wrote a poem praising him as "he writes two or three lines when drunk, but cannot write when he wakes up." Therefore, people later called Huai Su "Zui Su".
Many works by poets of the Tang Dynasty praised the wild cursive calligraphy of Zhang Xu and Huai Su. When Gao Shi described Zhang Xu in his poem, he said: "The calligraphy has become sacred since I was in the mood, and my words are still cool when I am drunk." Li Xin's poem to Zhang Xu is: "When I am in the mood, I sprinkle the plain wall, and my pen is like a shooting star." Su Huan chanted Huai Su cursive script It is described in the song: "When you are excited, your writing is like a whirlwind, and when you are drunk, your enthusiasm becomes even more ferocious." These Tang poems all described the creative state of Zhang Xu and Huaisu's cursive scripts, and had a great influence on later generations. People called them "epilepsy". "Zhang Zuisu" is the collective name of the two people.