Yáng Yúnsōng 楊筠松
Late-Tang / Five-Dynasties geomantic specialist; sobriquet Yáng Jiùpín 楊救貧 (“Yáng who saves the poor”). Per geomantic-school tradition (which the Sìkù 提要 of KR3g0021 dismisses as “absurd-talk, not entirely believable”): personal name Yì 益, native of Gànzhōu 贛州 (Jiāngxī); served as Língtái dìlǐguān (Spirit-Tower / Geomantic Officer) at the Tang court, rising to Jīnzǐ guānglù dàfū (Gold-and-Purple Glory-Salary Grand-Master); during the Guǎngmíng era (880-881) he allegedly stole secret palace texts during the Huáng Cháo rebellion and fled, settling in Chǔzhōu (Jiāngxī) where he worked as a wandering geomancer.
His historical existence is uncertain; the Sòngshǐ Yìwén zhì records only the sobriquet “Yáng Jiùpín”. But the geomantic tradition has consistently ascribed to him the foundational Yángshì 楊氏 / Jiāngxī pài 江西派 (Jiāngxī school) of xíngshì 形勢 (form-and-configuration) geomancy — the school that emphasizes the analysis of mountain-ridge dragons and water-flow patterns, in contrast to the Fújiàn pài (Fujian school) emphasis on directional compass-orientation.
The Yáng Yúnsōng trilogy preserved in the Sìkù: KR3g0021 Hànlóng jīng + Yílóng jīng + Zàngfǎ dàozhàng. Other works attributed to Yáng Yúnsōng but classified separately in the Sìkù: KR3g0022 Qīngnáng xù, KR3g0023 Qīngnáng àoyǔ, KR3g0024 Tiānyù jīng. Whether the historical Yáng Yúnsōng (if he existed) is the actual author of all these works, or whether the geomantic-school attributed them to a legendary founding-figure, cannot be determined from the available evidence.