Franco of Liège (died c. 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).
[1] [2] His De quadratura circuli, explaining his efforts to square the circle, was written around 1050.
[3] The musical treatise Quaestiones in musica, primarily ascribed to Rudolf of St Trond, has also been attributed to him.
[4] 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).