According to Netease's selected query, the four great calligraphers in Song Dynasty refer to Su Shi, Huang Tingjian, Mi Fei and Cai Xiang, not Li Bing.
Li Bing was an official in the court at the end of Shaoxing, the emperor of the Southern Song Dynasty (A.D. 1 162). He experienced three emperors, and finally managed the hospital in the palace with the title of "martial doctor" and begged the shrine in the palace to resign.