1. Huai Su (737~799), known as the "Cao Sheng" in history, was an outstanding calligrapher in the Tang Dynasty. His courtesy name is Zangzhen, his monk's name is Huaisu, and his common surname is Qian. He is Han nationality and a native of Lingling, Yongzhou (Lingling, Hunan). He is the nephew of Qian Qi, one of the ten talented men in the Dali calendar.
2. He became a monk since he was a child. During his free time from meditation, he devoted himself to cursive writing. He is as famous as Zhang Xu and is collectively known as "Dian Zhang Kuang Su". Two peaks in history. Huaisu's cursive calligraphy is thin and vigorous, with natural flying movements, like a sudden rain and whirlwind, changing at any time. Calligraphy is straightforward, ever-changing, and full of rules. Li Zhimin, a professor at Peking University and the founder of introducing monuments to cursive scripts, commented: "Huaisu's cursive script has a graceful spirit in its rush and ease, and a pure and honest spirit in its wildness."
3. The calligraphy works handed down from generation to generation include "Self-narrative Calligraphy", "Xiaocao Thousand-Character Essay" on paper, "Bitter Bamboo Shoots Calligraphy", "Notre Dame Calligraphy" and "On Calligraphy Calligraphy".