Alexander Neckam (1157-1217) was educated in Paris and taught in Dunstable and his native city of St. Albans, before he moved to Oxford to teach theology in the 1190s. Around the turn of the century he entered the Augustinian abbey of St. Mary's in Cirencester, where his productivity as a theological exegete, scholar and administrator led to his election as abbot in 1213. He attended the Fourth Lateran Council in 1215 and died two years later at Kempsey in England. He left a considerable literary legacy, including commentaries on the Song of Songs, Proverbs, Ecclesiastes, and the Psalms. The mythographic commentary he composed on the first two books of Martianus Capella's De nuptiis Philologiae et Mercurii stands out as the only extant work he devoted to a non-biblical work. It survives in two manuscripts from the fourteenth century, Oxford, Bodleian Library, Digby 221 and Cambridge, Trinity College, R. 14. 9 (884). This first edition offers a text based upon the two manuscripts and documents the sources upon which Neckam drew, which include Remigius of Auxerre, John the Scot, Helpericus and the Third Vatican Mythographer. The introduction reviews the medieval commentary tradition of the De nuptiis and assesses Alexander's contribution to it. An index of names concludes the work.