Detail of the Altar of St. Leo I the Great (Autel du pape Saint Leon Ier le Grand; Leo der Grosse) in the chapel of Our Lady of the Column.by Alessandro Algardi (1595-1654)The Meeting between Pope Saint Leo I the Great (440-461) and Attila the Hun is the only altarpiece in St. Peter's consisting of a monumental marble relief.It depicts the pope in 452 repelling Attila and the Huns from attacking Rome. Attila raises his arm as St. Peter and St. Paul appear in the sky.The altar is considered as the funeral monument of the Saint.( Saint Peter's basilica; basilique Saint-Pierre; Petersdom. )Vatican 2019