The Lincoln Thornton Manuscript is a medieval manuscript compiled and copied by the fifteenth-century English scribe and landowner Robert Thornton, MS 91 in the library of Lincoln Cathedral. The manuscript is notable for containing single versions of important poems such as the Alliterative Morte Arthure and Sir Perceval of Galles, and gives evidence of the variegated literary culture of fifteenth-century England. The manuscript contains three main sections: the first one contains mainly narrative poems (romances, for the most part); the second contains mainly religious poems and includes texts by Richard Rolle, giving evidence of works by that author which are now lost; and the third section contains a medical treatise, the Liber de diversis medicinis.