How to evaluate Yan Zhenqing's life?

Yan Zhenqing is a famous minister and a great master in the history of politics and calligraphy. Half of his life was spent in the complicated struggle with the imperial court on the battlefield. He devoted all his loyalty to the Tang Dynasty and really became a loyal and incorruptible minister. The other half of the time is spent studying. He studied art and literature and loved calligraphy. Through unremitting efforts, he reached the peak of a generation of calligraphers. In the history of calligraphy art in China, Wang Xizhi and Yan Zhenqing have the strongest artistic vitality, the deepest influence and the greatest lessons for later calligraphers. "Yan Ti" appeared in the Tang Dynasty and became a banner of regular script calligraphy. Its influence is even wider than that of Wang Xizhi, because "Yan Ti" is more easily accepted by the general public, and there are more people who wrote Yan Zi at the earliest than Wang Zi. In depth, many famous calligraphers were influenced by Yan Shu, and Liu Gongquan in the late Tang Dynasty got the essence of Yan Ti, which made the art of regular script in the Tang Dynasty reach another height. The four great calligraphers in Song Dynasty, Su Shi, Huang Tingjian, Cai Xiang and Mi Fei, were all deeply influenced by Yan Shu. After the invention of movable type printing in Song Dynasty, Yan style was mostly used in printing, and the fonts in Song Dynasty were mostly imitations, which shows that Yan calligraphy was popular at that time. Several calligraphers in Yuan Dynasty, such as Zhao Ziang and Xian Yushu, also studied "inkstone style". Many calligraphers in Ming and Qing Dynasties started with "Yan Ti". It has been 1200 years since Yan Zhenqing died, and the artistic style of "Yan Ti" still exists, which has influenced almost all calligraphers in later generations, which is really rare in the history of Chinese calligraphy art.