Peter Lombard (ca. 1096–1160) was a scholastic theologian and Bishop of Paris, best known as the author of the Sententiarum libri quatuor (Four Books of the Sentences), a systematic compilation of patristic and early medieval theological opinion organized around the doctrines of the Trinity, Creation, the Incarnation, and the Sacraments. Composed around 1150, the Sentences became the standard theological textbook of the medieval university, and every major scholastic theologian — including Aquinas, Bonaventure, Scotus, and Ockham — was required to lecture on it. Lombard studied in Bologna and Paris, taught at the cathedral school of Notre-Dame, and was appointed Bishop of Paris in 1159, a position he held until his death the following year.
