Nicholas, the name of five Popes: N. I., St., surnamed the Great, Pope from 858 to 867, asserted the supremacy of the papal see, Festival, Nov. 13; N. II., Pope from 1058 to 1061; N. III., Pope from 1277 to 1280; N. IV., Pope from 1288 to 1292; N. V., Pope from 1447 to 1456, after the capture of Constantinople by the Turks, took the exiled Greek scholars under his protection, fostered the learning of the East, and laid the foundation of the Vatican Library by the collection of over 5000 Greek and Latin MSS.