Born Tomasso Parentucelli (13 November 1397 - 24 March 1455), his father died when he was young, leaving Tomasso unable to complete his education until many years later. Achieving a degree in theology, he was hired by Bishop Niccolò Albergati, spending the next 20 years as the bishop's personal assistant and librarian, helping the bishop to acquire a large library. He read as well as curated; his wide knowledge of theology made him valuable and respected.
When Albergati died, Tommaso was offered the position of bishop, but Bologna was going through a some political troubles that made his appointment unlikely. Pope Eugene IV sent him on diplomatic missions at which Tommaso was so successful that he earned a cardinal's hat. Upon Eugene's death, Tommaso was elected to succeed him, taking the name Nicholas to honor his original patron.
He carried his love of learning and arts to the papacy. During his time:
—A library of 5000 volumes was created, including manuscripts rescued from Constantinople after it fell to the Turks. More on the evolution of the new Vatican Library can be found here.
—He promoted the new humanist learning, sending emissaries East to invite Greek scholars from Constantinople.
—He started his papacy by restoring the major Roman basilicas, and cleaning and paving main streets.
—He restored the Aqua Virgo, one of the 11 main aqueducts that used to supply the city before they crumbled into ruin after the fall of Rome. It emptied into a basin that later became the famous Trevi Fountain.
—He had Lorenzo Valla translate Greek histories and literature to make them available to the West.
As part of his rebuilding plan, he took 2522 cartloads of marble from the Colosseum, which at that time was used basically as a quarry. The Colosseum has been barely mentioned here, and you might be interested to know what the Middle Ages thought of this great Roman wonder...next time.