Arnold Nesselrath, an art historian who heads technical and scientific research at the Vatican Museums, told the Italian newspaper La Stampa that 16th century sources had offered clues. These sources said that Raphael had indeed painted two figures in the Apostolic Palace’s Hall of Constantine as tests of his oil technique.
In Nesselrath’s words, these figures were described as being “of a much higher quality than the ones around them.”
The exact identity of these figures was forgotten until the 21st century.
In an art restoration process that began in 2015, experts cleaned the works and removed the effects of centuries of previous restoration work.
They discovered that Raphael himself had painted two figures of women who serve as allegories for the virtues of Friendship and Justice. Only the art restoration made apparent Raphael’s oil technique.
The Hall of Constantine was intended to serve as a reception room in the Apostolic Palace of Vatican City. It depicts the life of the Constantine the Great, the first Roman emperor to seek baptism. The four frescoes depict The Vision of the Cross, the Battle of the Milvian Bridge, the Baptism of Constantine, and the Donation of Constantine.
The Vision of the Cross fresco depicts a key event said to have been a step towards Constantine’s conversion to Christianity during his battles to become emperor. The fresco depicts the emperor in a military camp looking towards giant cross in the sky that is surrounded by Greek words saying, “In this sign, conquer.”
At one side of this fresco, a woman labeled as Friendship wears a blue gown. She is seated to the left of St. Clement I, a first century Pope, the art blog Hyperallergic reports.
Another figure believed to be painted by Raphael is on the far right side of the fresco depicting Constantine’s battle at the Milvian bridge with his brother-in-law Maxentius, a rival imperial claimant. This woman’s image is labeled as Justice and bears a set of scales, at which she is staring.
Raphael, working under a commission from Julius II, had sketched plans for the Hall of Constantine before his death in 1520. The frescos’ completion was left to his students.
“They continued in the traditional method and have left only these two figures, autographs of the master,” Nesselrath told La Stampa.
Three other rooms in the Apostolic Palace feature Raphael’s work, including his famous depiction of the Greek philosophers Plato and Aristotle in his work “School of Athens.” Known as the "Raphael Rooms," the frescoes can be seen by visitors to the Vatican Museums.
Detail from the The Battle of the Milvian Bridge in the Hall of Constantine showing an allegorical Justice, lately found to be the work of Raphael, c. 1520.