Under Pope Sixtus IV specific quarters were established to house the volumes of manuscripts and the archives that formed the nucleus of the Vatican Library. In 1475 the library prepared the first catalogue of its holdings as a manuscript for internal use in the library. About 1477 Sixtus IV appointed Bartolomeo Platina prefect of the library. In 1481 when Platina produced a listing of the library's holdings, the library held over 3,500 items, making it by far the largest in the Western world.
Among his other accomplishments, Sixtus IV built the Sistine Chapel.
The first study in English "On the Vatican Library of Sixtus IV" was by John Willis Clark, who is better known for his classic work, The Care of Books. Clark published his study of the earliest Vatican Library in the Proceedings of the Cambridge Antiquarian Society No. XLI (Being the 10th vol., 4th vol. of New Series) 11- 61, with three plates.