Qí Lǚqiān 齊履謙 (1263–1329), zì Bóhéng 伯恒, native of Dàmíng 大名 (sometimes given as Shālù 沙鹿; modern Héběi). He was one of the leading Yuán mathematicians and calendrical scientists, eventually rising to Tàishǐyuàn shǐ 太史院使 (Director of the Astronomical Bureau). He served as Guózǐ sīyè 國子司業 in Yányòu 4 (1317), in which year he composed his self-preface to the Chūnqiū zhūguó tǒngjì 春秋諸國統紀 KR1e0059. Wú Chéng 吳澄 wrote the preface for him, treating him as a serious classical scholar in addition to his calendrical work. His biography is in Yuán shǐ 元史 j. 172. CBDB person 110780. He stands somewhat apart from the standard Yuán Chūnqiū school in that he came at the Chūnqiū with the analytical apparatus of an astronomer-calendrician.