Although he wrote sermons, letters, and commentaries on Holy Scripture, Lombard's Four Books of Sentences (1148-51) established his reputation and subsequent fame, earning him the title of magister senteniarum ("master of the sentences:). The Sentences, a collection of teachings of the Church Fathers and opinions of medieval masters arranged as a systematic treatise, marked the culmination of a long tradition of theological pedagogy, and until the 16th century it was the official textbook in the universities. Hundreds of scholars wrote commentaries on it, including the celebrated philosopher St. Thomas Aquinas.
