How to evaluate Yan Zhenqing's achievements in calligraphy?

Yan Zhenqing (708 ~ 784) was a famous calligrapher in the Tang Dynasty. His calligraphy is dignified, majestic and unique, which is called "Yan Ti" and passed down from generation to generation. Ink marks include confessions from official books and scripts to sacrifice my nephew. There are many pagodas, altars of Yan and Ma Xiangu, etc. Later generations compiled the Collection of Yan Wen.

Yan Zhenqing's calligraphy absorbed the artistic essence of the previous generation and contemporary calligraphers. Lu Yu, the tea god, said that his words won Wang Xizhi's heart and lungs. His brushwork was inherited by Zhang Xu, a calligrapher in the Tang Dynasty, and he consulted Huai Su, a famous monk. Yan Zhenqing's brushwork is very good. He once wrote twelve strokes. He is good at regular script and running script, especially regular script, which is praised by later generations. His glyph has the characteristics of a swallowtail silkworm head.

His calligraphy remains have always been cherished and highly respected by future generations. His superb calligraphy, like his noble character, can be immortal.