When Dante and Beatrice who is Theology first step out in Paradiso to the Moon, it is in the sphere of Faith.
The first Person on this lowest level he meets is Piccarda Donati.
Next he meets Empress Constance.Piccarda explains to Dante that her placement is due to "vows neglected and, in part, no longer valid." When she was alive, Piccarda, a nun, was forcibly removed from her convent by her brother Corso, in order to marry her to a Florentine man and further her family's political interests. She died soon after her wedding. In her acquiescence to her brother's wishes, though forced, she neglected her vows to God.
Through Dante's encounter with Piccarda, we first begin to learn about the nature of Heaven. For example, we learn that souls in Heaven become much more beautiful than they were on Earth; in fact, it takes Dante a while to actually recognize Piccarda as the woman he knew. In higher spheres, souls become so beautiful they cease to resemble their earthly selves. Piccarda is the only person Dante will recognize, unaided, in Heaven.
Thence to Mercury...where he meets Justinaian who the emperor - a talented orator driven to worldly achievement by the desire for honor and fame ~LorredanThis "great Constance" (Costanza) was the empress Constance (1152-98), wife of Henry VI, mother of Frederick II (the last dominant Holy Roman Emperor of the Middle Ages), and grandmother of Manfred. Like Piccarda, Constance was forced to leave her convent to enter into a political marriage. Dante's choice of Constance for the sphere of the Moon is a good example of his poetry of names, technically known as interpretatio nominis, which is based on an illuminating resonance between a person's name and his or her fate (or character). See Ciacco, Pier della Vigna, and Sapia. Here Dante exploits the traditional conception of the Moon as both the planet of Diana, the virgin goddess, and the planet of mutability or inconstancy. Piccarda, who was a "virgin sister" in the world, insists that though Costanza nominally broke her vows when she was forced to leave the convent, she nevertheless remained true to her promise--and thus to her name ("Constance")--in her heart.