fl. c. 1285

French astronomer about whom little is known except his surviving astronomical writings. We know he observed a conjunction of Saturn and Jupiter in 1285 and was writing around 1290. He wrote a calendar dedicated to Queen Marie of Brabant, which contradicted the church astronomical calculations of the time, and an Almanach that gave planetary positions accurate to within a minute of a degree. His use of observation over authority was novel at the time, and inspired later observational astronomers.