Twelve fresco panels by Renaissance painters decorate the Sistine Chapel’s two side walls. The north wall presents scenes from the life of Jesus, while the south wall presents scenes from the life of Moses. Together, the cycles create a visual comparison between the New Testament and the Old Testament.
Artists involved in the wall decoration included Perugino, Sandro Botticelli, Domenico Ghirlandaio, Cosimo Rosselli, Luca Signorelli, and Pinturicchio. The frescoes were produced mainly in the early 1480s, before Michelangelo painted the ceiling.
The number twelve applies to the major narrative panels on the two walls, not to every painted element in the chapel. Portraits, decorative details, lunettes, and later alterations are counted separately. Several original works were also lost or replaced, including a Perugino fresco removed when Michelangelo’s Last Judgment was created on the altar wall.