The chapel is on the piano nobile of the palace, and was one of the first decorations executed after the completion of the edifice by Michelozzo. Gozzoli painted his cycle over three of the walls, the subject being the Journey of the Magi to Bethlehem, but the religious theme was a pretext to depict the procession of important people who arrived in Florence in occasion of the Council of Florence (1438-1439). In this occasion the Medici could boast to have favoured the reconciliation between the Catholic and the Byzantine churches. The luxury of the Byzantine dignitaries is manifest, and shows the impression they would have at the time on the Florentine population.
Over a rich landscape probably influenced by Flemish artists (perhaps through tapestries), Gozzoli portrayed the members of the Medici family riding in the foreground of the fresco on the wall at the right of the altar. A young Lorenzo il Magnifico leads the procession on a white horse, followed by his father Piero the Gouty and the family founder, Cosimo. Then come Sigismondo Pandolfo Malatesta and Galeazzo Maria Sforza, respectively lord of Rimini and Milan: they did not take part in the Council, but were guests of the Medici in Florence in the time the frescoes were painted. After them is a procession of illustrious Florentines, such as the humanists Marsilio Ficino and the Pulci brothers, the members of the Art Guilds and Benozzo himself. The painter can be recognized for he is looking towards the observer and for the scroll on his red hat, reading Opus Benotii.
On the following wall, the bearded character on a white horse is the Byzantine emperor John VIII Palaiologos; the three girls next to him have been identified as the three daughters of Piero de' Medici, Nannina, Bianca and Maria. Finally, on the wall to the left of the altar are Pope Pius II, portrayed as an old man on a mule, preceded by Lorenzo's elder brother, Giuliano, carrying a leopard on his horse. In the same scene can be seen the Joseph, Patriarch of Constantinople and other Byzantine dignitaries, surrounded by exotic animals, such as a lynx and a falcon.
The lively colors and details of the frescoes are backed by the precious mosaics of the pavement, the gilted ceiling and the wooden stalls designed by Giuliano da Sangallo.
Gozzoli patron, Piero de' Medici, felt some of the seraphim were unsuitable, and wanted them painted over. Although the artist agreed to do this, it was never actually done.
In the 17th century, parts of the frescoes were destroyed to create access for a new staircase, where is the current entrance.