similar painting in the National Gallery, London, is also ascribed to Leonardo da Vinci, and ascribed a date before 1508. Originally thought to have been partially painted by Leonardo's assistants, a close inspection of the painting during the recent restoration between 2008 and 2010 has led the conservators from the National Gallery to conclude that the greater part of the work is by the hand of Leonardo, but debate continues. Parts of the painting, the flowers in particular, indicate the collaboration and have led to speculation that the work is entirely by other hands, possibly Leonardo's assistant Giovanni Ambrogio de Predis and perhaps Evangelista. It was painted for the chapel of the Confraternity of the Immaculate Conception, in the church of San Francesco Maggiore in Milan. It was sold by the church, very likely in 1781, and certainly by 1785, when it was bought by Gavin Hamilton, who took it to England. After passing through various collections, it was bought by the National Gallery in 1880. Angels Two paintings of angels playing musical instruments are believed to have been part of the composition that was set into the altarpiece. These two pictures, now in the National Gallery, London, are thought to have been completed between 1490 and 1495. One, an angel in red, is thought to be the work of Ambrogio de Predis while the angel in green is thought to be the work of a different assistant of Leonardo, perhaps Francesco Napoletano. History Chapel of the Immaculate Conception The Chapel of the Immaculate Conception was founded prior to 1335 by Beatrice d'Este, wife of Gian Galeazzo Visconti, Duke of Milan. The chapel was attached to the church of S. Francesco Grande, Milan. In 1479 the Confraternity of the Immaculate Conception contracted Francesco Zavattari and Giorgio della Chiesa to decorate the vault of the chapel. In 1480 the Confraternity of the Immaculate Conception contracted Giacomo del Maino to create a large wooden altarpiece with spaces for paintings and with carvings and decoration, to be placed above the altar of the chapel. Final payment was to be made on August 7, 1482. Commission for the painting On April 25, 1483, Prior Bartolomeo Scorlione and the Confraternity contracted Leonardo da Vinci, and the brothers Ambrogio and Evangelista de Predis to provide the painted panels for the altarpiece. The contract was not explicit about what each artist was to do. Leonardo was referred