Ōuyáng Xún 歐陽詢 (557–641), zì Xìnběn 信本, native of Línxiāng 臨湘 in Tánzhōu 潭州 (modern Húnán). CBDB id 3685. His father Ōuyáng Hé 歐陽紇 was a Chén-period general whose failed revolt against the throne in 569 cost him his life and would have cost the young Xún his as well, had he not been hidden by his father’s friend Jiāng Zǒng 江總 — who then raised him and oversaw his education. Despite an unprepossessing appearance — the Jiù Táng shū records that Suí Yángdì laughed at his face when he received him in audience — Ōuyáng’s talents were recognized early. Under the Suí he held Tàicháng bóshì 太常博士; entering the Táng under Gāozǔ he served as Tàizǐ shuàigēng lìng 太子率更令 (Bureau of Water-clocks in the Crown Prince’s household) and Hóngwén guǎn xuéshì 弘文館學士, with the title Earl of Bóhǎi 渤海男. He died in Zhēnguān 15 (641) at the age of 84.
He is remembered above all as one of the four founding masters of regular-script (kǎishū 楷書) calligraphy of the Táng — known as “Ōutǐ” 歐體 — alongside Yú Shìnán 虞世南, Chǔ Suìliáng 褚遂良 and Xuē Jì 薛稷. His surviving steles, particularly the Jiǔchéng gōng Lǐquán míng 九成宮醴泉銘 (commemorating Wèi Zhēng 魏徵’s 632 stele) and the Huàdù sì Yōng chánshī tǎ míng 化度寺邕禪師塔銘, were standard models for calligraphy practice through the Sòng and into the modern period. His Sānshíliù fǎ 三十六法, a treatise on the geometry of regular-script structure attributed to him, is the foundation of the Chinese pedagogy of brush composition. His other major output is the Yìwén lèijù 藝文類聚 (KR3k0003), the foundational early-Táng lèishū in 100 juan, completed in 624, of which he was the principal compiler. His biographies are in Jiù Táng shū 189 (上) and Xīn Táng shū 198.