Forty ancestors of Christ are represented in the Sistine Chapel’s lunettes and spandrels.
The number follows the genealogy at the beginning of the Gospel of Matthew, which traces Christ’s lineage from Abraham through forty generations. Michelangelo translated that genealogy into a sequence of painted family groups and figures positioned above the chapel’s windows.
The lunettes are the curved panels directly over the windows. The smaller triangular spandrels above them probably extend the same genealogical theme, although many of their individual figures cannot be identified with certainty. Names appear on the decorative tablets, but the scenes are not straightforward historical portraits.
A common mix-up is confusing the forty generations in Matthew with Luke’s genealogy, which gives a different and longer lineage beginning with Adam. The four large corner pendentives are also sometimes counted incorrectly: they depict dramatic episodes of Israel’s salvation, not additional ancestor groups. Two original lunettes were later destroyed when the altar wall was altered for Michelangelo’s Last Judgment.