Lǐ Gǎo 李杲 (zì Míngzhī 明之, self-styled Dōngyuán lǎorén 東垣老人, 1180–1251), the third of the canonical JīnYuán “Four Masters” and founder of the Spleen-and-Stomach school (補土派 / 脾胃派) of Chinese medicine. Native of Zhēndìng 真定 (Héběi). Briefly served as Tax Inspector at Jǐyuán 濟源 by purchase of office. Originally took up medicine after his mother died from an illness no physician understood. Studied with 張元素 Zhāng Yuánsù of Yìzhōu, paying 1000-pieces-of-gold for the apprenticeship; eventually surpassed his teacher in reputation. Spans the JīnYuán transition: 55 years old at the Jīn collapse (1234), lived 17 years more under Yuán rule. Biography: Yuán shǐ Fāngjì zhuàn. Yán Jiān 硯堅’s Dōngyuán lǎorén zhuàn is the principal contemporary biography. Major works: Nèiwài shāng biànhuò lùn 內外傷辯惑論 (KR3e0052, 3 juan, completed 1231 / Jīn Zhèngdà 9, published 1247); Píwèi lùn 脾胃論 (KR3e0053, 3 juan, ca. 1247–1249) — the foundational text of the school; Lánshì mìcáng 蘭室秘藏 (KR3e0054, 3 juan); Yī xué fāmíng 醫學發明 (TBD). Lǐ Gǎo’s signature prescription, the Bǔzhōng yìqì tāng 補中益氣湯 (Center-Tonifying Qi-Boosting Decoction), remains a standard formulation in modern TCM. The school’s transmission line — Zhāng Yuánsù → Lǐ Gǎo → Wáng Hǎogǔ → Luó Tiānyì — is one of the most influential lineages in Chinese medical history. The catalog meta gives the dynasty as 元 (Yuán), correct given his late-career activity under Yuán rule.