history
Yan Zhenqing served as a loyal Tang official during the An Lushan Rebellion (安史之乱), losing his nephew Yan Jiming to rebels. His grief-stricken eulogy 《祭侄文稿》 (Jì Zhí Wén Gǎo, 'Draft of a Eulogy to a Nephew') survives as a manuscript with crossings-out and corrections - and is regarded as one of the three greatest works of running-script calligraphy in history. He was eventually executed at age 76 after refusing to defect to a rebel general.
culture
Founder of the 颜体 (Yán tǐ) style - characters with thick, heavy strokes, square structure, and an upright moral feeling. His style is paired with Liu Gongquan's (柳公权) in the saying 颜筋柳骨 (yán jīn liǔ gǔ, 'Yan's sinews, Liu's bones'). Beginners learning Chinese calligraphy almost always start by copying his 《多宝塔碑》.