Morgan Library MS M.905 (the Geese Book) is the last known illuminated gradual produced for the Church of St. Lorenz in Nuremberg, Germany. The Geese Book, which was created during the early sixteenth century, has been in the collection of the Morgan Library since 1961. This thesis describes the iconography of the eight historiated initials that illustrate the earthly life of Christ from the Annunciation to the Ascension. A detailed description of the content of each initial is followed by a brief history of the iconographic development of the identified event in order to determine whether or not the Geese Book uses a standard or nonstandard iconography. The results of this analysis reveal how this manuscript fits into the broader contexts of Christian art as well as the specific time and place of its creation. It shows that the iconography of the Geese Book reflected current theological beliefs and societal norms and allowed contemporary viewers of the Geese Book to feel a strong connection to the depicted events.