The Laurentian library was built in Florence to house the collection of books gathered by Cosimo de'Medici (1389-1464) and greatly enlarged by his grandson Lorenzo (1449-92). Giulio de'Medici commissioned Michelangelo as architect, and building work began after Giulio was elected as Pope Clement VII in 1523. Michelangelo came under intense pressure to work quickly; the correspondence between him and Clement is one of the most fascinating records of a creative dialogue between a sixteenth-century patron and an architect.These studies, one on each side of a single sheet, are designs for the door between the vestibule, or ricetto, and the Laurentian library. The recto shows the side of the door visible from inside the library, while the other side is shown on the verso. The designs are different from each other because the door in the vestibule had to be fitted into a narrower bay, which explains the lack of columns at the side.The door needed a blank panel above the opening for a dedicatory inscription on the vestibule side and this is shown in all the sketches. In the finished design more space had to be found as Clement wanted a Latin inscription of between 100 and 140 letters and went to considerable trouble in finding one he liked.