Huai Su (737-799) was a calligrapher in the Tang Dynasty. He is famous for "Weeds" and is known as the "sage in the grass" in history. Being a monk since childhood, I like calligraphy after meditation. And Zhang Xu, collectively referred to as "Dian Zhang Kuang vulgar".
Huai Su's cursive script is thin and vigorous, flying naturally, like a whirlwind of showers. Although his calligraphy is capricious and ever-changing, it has statutes. Huai Su and Zhang Xu formed two peaks of calligraphy in Tang Dynasty, and also two peaks in the history of cursive script in China.
Calligraphy works handed down from ancient times include autobiographical notes, bitter bamboo shoots, Notre Dame notes, essays on books, a thousand grasses and so on.