The Third Lateran Council, convened by Pope Alexander III in March 1179, passed twenty-seven canons addressing abuses in the Church and condemning the Cathar and Waldensian heresies. The council also required cathedral churches to provide free schooling for the poor, a measure with lasting consequences for the spread of literacy in Europe. It addressed simony, nepotism, and the conduct of clergy, reflecting the reform spirit that had been gathering force since the Gregorian reform of the previous century. The council's condemnation of heresy sharpened the distinction between orthodox and heterodox that would shape religious culture for decades.

The council's mandate for cathedral schools expanded access to basic Latin education, broadening the pool of literate writers and readers from which vernacular literature would eventually emerge. Its condemnation of the Cathars set in motion the ideological framework that culminated in the Albigensian Crusade — the event that destroyed the troubadour courts of southern France. Waldensian preachers, who translated scripture into vernacular tongues for popular audiences, represented an early force for vernacular literary culture that the council sought to suppress.