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.