Zhang Xu, born in the third year of Shangyuan of Tang Dynasty (675) and died in the ninth year of Tianbao of Xuanzong (750), was born in Wujun (Suzhou, Jiangsu). His first official position was Changshu Wei, and his later official position was Changshi in Jinwu, where he was known as "Zhang Changshi". His mother, Lu, was the niece of Lu Jianzhi, a calligrapher in the early Tang Dynasty, and the granddaughter of Yu Shinan. The Lu family passed down their business through books from generation to generation, which is well-known in history. Zhang Xu is free and uninhibited, open-minded, outstanding, talented and knowledgeable. Being friendly with Li Bai and He Zhizhang, Du Fu listed the three of them among the "Eight Immortals in Drinking". He is a very unique cursive calligrapher. Because he often gets drunk, he screams and runs away, and then writes a book. He even writes with his hair dipped in ink, so he is also known as "Zhang Dian". Hou Huaisu inherited and developed his writing style, which was also named after cursive script, and was also called "Dian Zhang Zuisu". Zhang Xu has a bold personality and is fond of drinking. He often dances when he is drunk, then returns to the table, picks up the pen and writes ink, and writes in one stroke. Some people said he was rude and gave him the nickname Zhang Dian. In fact, he is very careful. He believes that everything he touches in daily life can inspire writing. What I get by chance is melted into my own calligraphy. At that time, as long as people got a scrap of his writing, they regarded it as a treasure and inherited it hereditary. At that time, Zhang Xu had a neighbor who was from a poor family. Hearing that Zhang Xu was generous, he wrote to Zhang Xu, hoping to get his support. Zhang Xu sympathized with his neighbor very much, so he wrote in the letter: As long as you say that this letter was written by Zhang Xu, the asking price can be hundreds of gold. The neighbor took the letter to sell on the street according to his words, and sure enough, it was sold out in less than half a day. The neighbor returned home happily and expressed his deep gratitude to Zhang Xu.
Zhang Xu’s calligraphy was first developed by Zhang Zhi and Er Wang, with his highest achievement in cursive script. Known as the "Grass Saint" in history. He himself is proud to inherit the tradition of the "Two Kings", and his every word is legal. On the other hand, he imitates Zhang Zhi's cursive calligraphy skills and creates wild cursive calligraphy that is free and upright, unpredictable and shocking to the world. According to legend, he saw the princess fighting with the bearer and learned the meaning of calligraphy from the advocacy. When he was in Ye County, Henan, he loved to watch Lady Gongsun dancing with the Xihe sword, and he became the god of cursive calligraphy. Yan Zhenqing resigned from office twice and asked him for advice on penmanship. Zhang Xu is a pure artist. He pours his full emotions into the dot paintings, as if there is no one else around, intoxicated and crazy. Han Yu of the Tang Dynasty praised it in his "Preface to Master Gao Xian": "Happiness, anger, embarrassment, sadness, joy, resentment, longing, drunkenness, boredom, injustice, whatever moves the heart, must be expressed in cursive writing. Looking at things, one can see mountains, rivers, cliffs and valleys, birds, beasts, insects and fish, vegetation and flowers, sun, moon and stars, wind, rain, fire, thunder and thunder, songs, dances and battles, changes in things in the world, joy and astonishment, all of which are contained in books, so the book of the rising sun , Changes like ghosts and gods, unpredictable, and will be famous for the rest of his life. "This is a true portrayal of a true artist's persistence in art. No wonder later generations have praised and criticized Ou, Yu, Chu, Yan, Liu, Su, etc. when discussing Tang calligraphy, but they all praise Zhang Xu. This is unique in the history of art.