Despite Latin being the main language of the courts and the Church in the Middle Ages, writers such as Dante Alighieri and many others used their own language, the Florentine vernacular descended from Latin, in composing their greatest works. The oldest literary pieces written in Florentine go as far back as the 13th century. Florence's literature fully blossomed in the 14th century, when not only Dante with his "Divine Comedy" (1306–1321) and Petrarch, but also poets such as Guido Cavalcanti and Lapo Gianni composed their most important works. Dante's masterpiece is the "Divine Comedy", which mainly deals with the poet himself taking an allegoric and moral tour of Hell, Purgatory and finally Heaven, during which he meets numerous mythological or real characters of his age or before. He is first guided by the Roman poet Virgil, whose non-Christian beliefs damned him to Hell. Later on he is joined by Beatrice, who guides him through Heaven.