What experiences does Liu Gongquan have?

Liu Gongquan (778~865), courtesy name Chengxuan, was born in Huayuan, Jingzhao (now Yaoxian County, Shaanxi Province) and was the last great calligrapher of the Tang Dynasty. He was a Jinshi at the age of 31 and served in seven dynasties including Xianzong, Mu Zong, Jingzong, Wenzong, Wuzong, Xuanzong and Yizong. He was an official in the capital basically all his life. Liu Gongquan took over the banner of regular script from Yan Zhenqing and created his own "Liu style", reaching another pinnacle of Chinese calligraphy. He changed the plump style of calligraphy in the mid-Tang Dynasty. He used the pen sharply and vigorously, with deep bone strength. He focused on the square and supplemented it with the round. He was strict in law but fresh and straight, and had an artistic realm of thinness, toughness and spirituality. This is the famous "willow bone". "Liu style" is as famous as "Yan style", and is also called "Yan Jin Liu Gu". It is the most influential calligraphy style in the history of Chinese calligraphy. The handed down works include "Prince Taifu Liu Mian Stele", "Wei Gongxian Temple Stele", "Gao Yuanyu Stele", "Mysterious Tower Stele", "Shence Army Stele" and so on.