Crazy grass calligraphy "begins with Zhang and ends with Su". Which two famous people in history do Su Zhang and He refer to?

"Zhang" refers to Zhang Xu and "Su" refers to Huai Su. It is said that the legend of weeds originated from Ren You, experienced Zhang Zhi and Wang Xizhi, and began to spread widely in Zhang Xu and Huai Su in the Tang Dynasty.

Zhang Xu is called "the sage of grass". He is a contemporary of Li Bai because of his bold personality. He likes drinking and is Li Bai's drinking buddy. Li Bai has the reputation of hundreds of poems about fighting wine, and so does Zhang Xu. Only when he is drunk can he create with unusual passion and write with unusual boldness, while the dragon and phoenix dances with extraordinary momentum, so his calligraphy is called "Wild Grass" and later generations call it "Zhang Dian". Zhang Xu's cursive script, Li Bai's poems and songs, and Pei Min's sword dance are called Three Musts. Works handed down from ancient times include the cursive poem Four Words. According to folklore, he often gets drunk and then runs wild. Wherever he went, he began to write, even with his hair dipped in ink.

After Zhang Xu, there was a man named Huai Su. He is also unrestrained. Although he is a monk, he drinks and eats meat. He is called "crazy monk". Similarly, after being drunk, the things written are also chic and magnificent. It also has the reputation of wild grass calligraphy.

The formation of cursive script probably went through several periods. Beginning in the early Han Dynasty, general official script developed into scribbled official script and "Cao Li", and calligraphy changed from Zhang Zhi to "modern grass". In the Tang Dynasty, Zhang Xu and Huai Su developed into Weeds. As for madness, it is because later generations think that Zhang Xu's writing style can jump out of Wang Xizhi's and Wang Xianzhi's imprisonment, which has obvious times and has a new way. Huai got the true meaning of weeds and went forward bravely, which later generations could not compare with.