Humphrey, Duke of Gloucester, has long been recognized as the leading patron of the new learning in England in the fifteenth century. His collection has been called ‘ … the most important in England at his time. Other libraries, such as Christ Church, Canterbury, St. Albans, or Peterborough, may have exceeded it in numbers, but Duke Humphrey's books could display a greater variety of subjects, and included many works to be found nowhere else in the country.' Unfortunately, few MSS are still extant which can be identified as having belonged to him. We do have, however, a good indication of the scope of his library from the surviving lists of books which he gave to Oxford University.

From letters of Ambrosius Traversarius, edited by Cannetus and published with the Vita Ambrosii Traversarii of Mehus, it is known that Ambrosius Traversarius translated the Vita Gregorii Nazianzeni written by Gregorius Presbyter and also four orations of Gregory Nazianzene, numbers 18, De Obitu Patris, and 6, 23, and 22, the three orations De Pace. The Vita with its dedicatory letter is preserved in at least eight manuscripts, but no trace of the orations has been found. Our information concerning the translation of the orations comes from the letters written by Ambrosius in the year 1436.

Scholars interested in Ambrosius Traversarius have uncovered no further information on these Latin translations. Ludwig Bertalot found twelve additional letters not contained in the collection of Cannetus.