Shākèshí 沙克什 (1278–1351), originally 贍思 Shànsī (the form 沙克什 was a Sìkù-era retransliteration; the original 贍思 form is closer to the medieval Persian Shamsi), zì Zǐtíng 子亭, was a Yuán-era polymath of Western Regions Muslim (Sěmù 色目) background. His ancestors had migrated from the Western Regions; he himself was born and educated in north China and rose to Mìshū shǎojiān 祕書少監 (Junior Vice-Director of the Imperial Library). The Yuánshí biography (j. 190) places him among the major Yuán Confucian classicists of Sěmù origin and credits him with proficiency in astronomy, geography, music-theory, and mathematics in addition to hydraulic engineering. He produced a Sìshū kuóyào 四書闊要 commentary, a dictionary of Confucian terminology, and a major astronomical study. His principal surviving work is the revised Héfáng tōngyì (KR2k0063), a 2-juan technical manual on Yellow River flood-control consolidating the Northern Sòng manual of Shěn Lì 沈立 with the Jīn-era Imperial Waterways Commission handbook. CBDB has no confident entry for him under either form.