One of the oldest libraries in the world, it preserves the manuscripts collections begun by Cosimo the Elder (1389-1464) and expanded by his son Peter (1416-1469) and, even more actively, by his nephew Lorenzo the Magnificent (1448-1492). The construction of its present home, next to the Basilica of San Lorenzo in Florence, began in 1524. The plans were drawn by Michelangelo Buonarroti, who had received the commission from Clement VII (1478-1534, Pope from 1523), a member of the Medici family. When the library opened in 1571, it had about 3,000 manuscripts. The Grand Dukes of Lorraine improved the facility, encouraging scholars to use it. Today, it houses 530 incunabula and 10,208 manuscripts, many of them priceless.