The decoration of this room, which dragged out for years, was commenced in 1624. The following year Jacopo Vignali frescoed the ceiling with the Eternal Father separating Light from Darkness and personifications of Night and Day, which give the “chamber” its name, and the upper part of the walls with a frieze in which pairs of putti hold coats of arms of families related to that of the Buonarroti. Work resumed several years later with the construction of the “Scrittoio”, where Michelangelo the Younger used to retire to study. The wooden section of this small room was executed in 1629 by Francesco da Sant’Andrea a Rovezzano and the paintings by Baccio del Bianco, who at the same time paint- ed the graceful mock doors on the walls in oil. The decoration of the room was completed in 1637-1638, with the depiction of members of the Buonarroti family and events connected with them by various artists, including Pietro da Cortona, who portrayed Buonarroto being made a count palatine by Pope Leo X.
On the walls are set Giovanni di Francesco’s masterpiece, the Scenes from the Life of Saint Nicholas of Bari, a marble Cupid, begun by Valerio Cioli (1529-1599) and finished by Andrea di Michelangelo Ferrucci (died in 1626); the portrait of Michelangelo painted by Giuliano Bugiardini (1475-1555); and the one of Michelangelo the Younger by Cristofano Allori (1577-1621). The bronze head of Michelangelo is the work of Daniele da Volterra.