39 Shortly after his death, churches dedicated to the Seraphic Father and admirable for the beauty of their architecture and treasures of art began to rise, due to the wishes of the people to honor him. The most famous artists competed one with another as to who should succeed in portraying with the greatest perfection and beauty the likeness and life of Francis in paintings, in statues, in engravings, and in mosaics. Thus Santa Maria degli Angeli was built on that very plain where Francis "poor and humble entered rich into heaven." Churches, too, were built at the place of his glorious burial as well as on the hills of Assisi, and to these pilgrims flocked from everywhere in small parties or in large groups, in order to recall for the benefit of their souls the memory of so great a saint and to admire these immortal monuments of art. Moreover, there arose to sing the praises of the Man of Assisi, as We have already seen a poet who has no equal, Dante Alighieri. He was followed by others both in Italy and elsewhere who brought glory to literature by exalting the grandeur of the saint.
Source: Rite Expiatis (Vatican.va)