The Sistine Chapel is a chapel in the Apostolic Palace, the official residence of the pope, in Vatican City. Originally known as the Cappella Magna ('Great Chapel'), the chapel takes its name from Pope Sixtus IV, who restored it between 1473 and 1481. Since that time, the chapel has served as a place of both religious and functionary papal activity. Today, it is the site of the papal conclave, the process by which a new pope is selected. The fame of the Sistine Chapel lies mainly in the frescos that decorate the interior, most particularly the Sistine Chapel ceiling and The Last Judgment by Michelangelo. During the reign of Sixtus IV, a team of Renaissance painters that included Sandro Botticelli, Pietro Perugino, Pinturicchio, Domenico Ghirlandaio and Cosimo Rosselli, created a series of frescos depicting the Life of Moses and the Life of Christ, offset by papal portraits above and trompe-l'œil drapery below. These paintings were completed in 1482, and on 15 August 1483 Sixtus IV celebrated the first mass in the Sistine Chapel for the Feast of the Assumption, at which ceremony the chapel was consecrated and dedicated to the Virgin Mary. Between 1508 and 1512, under the patronage of Pope Julius II, Michelangelo painted the chapel's ceiling, a project which changed the course of Western art and is regarded as one of the major artistic accomplishments of human civilization. In a different climate, after the Sack of Rome, he returned and, between 1535 and 1541, painted The Last Judgment for Popes Clement VII and Paul III. The fame of Michelangelo's paintings has drawn multitudes of visitors to the chapel ever since they were revealed five hundred years ago. While known as the location of Papal conclaves, the primary function of the Sistine Chapel is as the chapel of the Papal Chapel (Cappella Pontificia), one of the two bodies of the Papal household, called until 1968 the Papal Court (Pontificalis Aula). At the time of Pope Sixtus IV in the late 15th century, the Papal Chapel comprised about 200 people, including clerics, officials of the Vatican and distinguished laity. There were 50 occasions during the year on which it was prescribed by the Papal Calendar that the whole Papal Chapel should meet. Of these 50 occasions, 35 were masses, of which 8 were held in Basilicas, in general St. Peter's, and were attended by large congregations. These included the Christmas Day and Easter masses, at which the Pope himself was the celebrant. The other 27 masses could be held in a smaller, less public space, for which the Cappella Maggiore was used before it was rebuilt on the same site as the Sistine Chapel. The Cappella Maggiore derived its name, the Greater Chapel, from the fact that there was another chapel also in use by the Pope and his retinue for daily worship. At the time of Pope Sixtus IV, this was the Chapel of Pope Nicholas V, which had been decorated by Fra Angelico. The Cappella Maggiore is recorded as existing in 1368. According to a communication from Andreas of Trebizond to Pope Sixtus IV, by the time of its demolition to make way for the present chapel, the Cappella Maggiore was in a ruinous state with its walls leaning. The present chapel, on the site of the Cappella Maggiore, was designed by Baccio Pontelli for Pope Sixtus IV, for whom it is named, and built under the supervision of Giovannino de Dolci between 1473 and 1481. The proportions of the present chapel appear to closely follow those of the original. After its completion, the chapel was decorated with frescoes by a number of the most famous artists of the High Renaissance, including Sandro Botticelli, Domenico Ghirlandaio, Pietro Perugino, and Michelangelo. The first mass in the Sistine Chapel was celebrated on 15 August 1483, the Feast of the Assumption, at which ceremony the chapel was consecrated and dedicated to the Virgin Mary. The Sistine Chapel has maintained its function to the present day and continues to host the important services of the Papal Calendar, unless the Pope is travelling. There is a permanent choir, the Sistine Chapel Choir, for whom much original music has been written, the most famous piece being Gregorio Allegri's Miserere.