The reading habits of the author of Sir Gawain and the Green Knight, Pearl, Purity, and Patience remain a fascinating and fruitful field of study. Much has been written about the books the poet read, or may have read, but it is unlikely that the catalogue of books owned or read by him has by any means been completely reconstructed. Of the books he certainly knew, the Vulgate is of first importance for its influence upon the poet's thought and style. Certain, but less important, are the Romance of the Rose and the French text of Mandeville. Of the books very probably read by him the Divine Comedy stands first, followed by the Vita Nuova and the Convivio, Boccaccio's Olympia, and the Consolation of Philosophy of Boethius. Less probable is his reading of Tertullian's De Patentia and De Jona et Ninive, the Travels of Marco Polo, Peter Comestor's Historia Scholastica, the Book of the Knight of La Tour-Landry, the French lapidaries, and a few others still less certain.