Franco of Liège

Franco of Liège (died {{circa|1083}}) was an 11th-century mathematician who worked on squaring the circle. He was the chancellor (attested 1057) and later scholaster of Saint Lambert's Cathedral, Liège (before 1066-after 1083).Menso Folkerts and Barnabas Hughes, "The Latin Mathematics of Medieval Europe", in Sourcebook in the Mathematics of Medieval Europe and North Africa, edited by Victor J. Katz (Princeton University Press, 2016), pp. 50-53. F.P.C. De Jong, "A Comparative Study of Schoolmasters in Eleventh Century Normandy and the Southern Low Countries", Ph.D. thesis, 2018

His De quadratura circuli, explaining his efforts to square the circle, was written around 1050.Menso Folkerts and A. J. E. M. Smeur, "A Treatise on the Squaring of the Circle by Franco of Liège, of about 1050", Archives d'histoire des sciences, 26 (1976), pp. 59-105, 225-253. The musical treatise Quaestiones in musica, primarily ascribed to Rudolf of St Trond, has also been attributed to him.Dolores Pesce, The Affinities and Medieval Transposition (Indiana University Press, 1987), pp. 39-40. Sigebert of Gembloux ascribes to him other works, including some saints' lives, a poem (ligno crucis) and a treatise on the ember days (De Jejunio IIIIor temporum).

Cosmas of Prague was his student. Cosmas of Prague, "The Chronicle of the Czechs", translated by L.Wolverton, CUA Press, 2009, p.249.