The historic Pietro della Vigna was an Italian lawyer whose skill gained the attention of the Holy Roman Emperor, Frederick II. The emperor made Vigna his Chancellor as well as his representative abroad. Vigna was an excellent diplomat to Frederick, handling negotiations with the Pope as well as arranging the emperor's marriage to an English princess. However, Vigna's fall from grace began when he designated another jurist to defend Frederick against the accusations of Pope Innocent IV, which failed. After an assassination attempt against Frederick, Vigna was falsely accused of the crime and imprisoned. When Frederick later confronted his former chancellor on charges of attempted murder, heresy and offending the dignity of his sovereign, Vigna was unable to defend himself against the accusation. In response, the emperor had the lawyer's eyes gouged out. Unwilling to take this disgrace any longer, Vigna committed suicide by smashing his head repeatedly against a stone wall of his prison, crushing his skull.
- In The Inferno, as they went through the Suicide Woods, Dante and Virgil behold the tree that houses the soul of Pietro della Vigna. He then speaks with Dante, telling the poet his sad tale. Dante placing Vigna in this circle rather than in a lower one suggests that he believed the accusations against the former chancellor to have been false.