Construction was begun in 1255 by the Franciscan Order, which still has a monastery here. The portal is noted for its richly decorated triple false arches, while the exquisite rose window above the main entrance is the epitomizes medieval Latin church architecture. The facade, built in the early 1300s by the Ventimiglia, Abbatelli and Chiaramonte families, is not unlike that of the Church of Sant' Agostino, but inside St. Francis retains a much more medieval flavor. The church has a nave with magnificent arches, and also a beautiful cloister. A side chapel is dedicated to the Sicilian branch of the Grimaldi family, better known in Genoa and Monaco.
Some scholars believe that a temple existed here in Roman, or possibly even Punic, times.
This was turned into a mosque. In 1072, when the Normans wrested control of Palermo from the Saracens, Count Roger promptly saw to it that the Great Mosque was reconsecrated as a Christian church. The present cathedral was not completed for another century, and greatly modified through the ages. In 1185, the English Archbishop of Palermo, Walter of the Mill, assumed responsibility for the completion of the cathedral. We know not precisely when the remains of Odo of Bayeaux, brother of William the Conqueror, were interred here, but it may have been while Walter was bishop.