Leo de Benedicto Christiano, or just Benedictus Christianus, was a Jew of Trastevere in the late eleventh century.
In January 1058, as a partisan of the newly elected Pope Nicholas II, Leo had the gates of the Leonine City thrown open for Godfrey, former duke of Lower Lorraine, and his wife, Beatrice, marchioness of Tuscany.
Godfrey immediately possessed the Tiber Island and attacked the Lateran, forcing Benedict X to flee on 24 January.
His son was Pier Leoni and through him he is the father of the great Pierleoni family which dominated Roman politics for much of the Middle Ages.
So far as one can tell, he lived in peace with the Roman people and the pontiff, but his grandson, who was elevated to the papacy as Antipope Anacletus II, was lambasted for his Hebrew ancestry; as was another grandson, Jordan, who was elected patrician of the Commune of Rome and became also an enemy of the legitimate popes.