What are the records about the emperor and his masterpiece Urgent Chapter?

The emperor was born in Jiangdu, Guangling (now Yangzhou, Jiangsu), and his date of birth and death is unknown. A famous calligrapher in Wu Dong during the Three Kingdoms period. Zeng Guan went to China and Qingzhou for secretariat. Good at eight points, small seal script, especially good at zhangcao. His Cao Zhang, Cao Buxing's paintings and Yanwu's Weiqi are also called "Eight Wonders". The Emperor's Cao Zhang is wonderful, and the masterpiece is Urgent Chapter. Urgent Chapter is an ancient literacy textbook. The "urgent chapter" written by calligraphers handed down from ancient times was first written by the emperor. Its engraving is the most famous "Songjiang Edition". The original stone carving is now in Shanghai Songjiang County Museum. There are as many as 1394 words. Clear strokes and standard structure are good examples for learning from Cao Zhang.