Sistine Chapel ceiling restoration began on 7 November 1984. The restoration complete, the chapel was re-opened to the public on 8 April 1994. The part of the restoration in the Sistine Chapel that has caused the most concern is the ceiling, painted by Michelangelo. The emergence of the brightly coloured Ancestors of Christ from the gloom sparked a reaction of fear that the processes being employed in the cleaning were too severe and removed the original intent of the artist. The problem lies in the analysis and understanding of the techniques utilised by Michelangelo, and the technical response of the restorers to
Sistine Chapel 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.