The colossal statue of Constantine comes from the Basilica Nova in Rome, which was started by Maxentius and finished by Constantine after he defeated Maxentius in 312. This unique portrait of Constantine is one of the most important statues of Late Antiquity. It is possible that Eusebius referred to the statue in his works, the Life of Constantine and the Ecclesiastical History, which also records its inscription.

Fragments of the statue, discovered in 1486 in the western apse of the Basilica Nova, are now in the courtyard of the Palazzo dei Conservatori of the Capitoline Museums.  Additional fragments of the statue (the left breast and the right arm) were discovered in 1951. The fragments, which are made of Parian and Carrara marble, include the head and neck, the right leg from the knee to the foot, the left leg below the knee and the left foot, part of the right arm and the right hand. The fragment of the head and neck is around 2.5 meters, while the right hand is 1.66 meters, meaning the statue could have been as much as 12 meters tall. The position of the left foot, with heel raised, confirms that it was a statue of a seated figure of an emperor. The statue was bare-chested and was probably was placed on a pedestal. Marble was used to portray the exposed flesh, while the mantle might have been bronze. The dowel holes on the temples suggest that a diadem was attached to the brow, while the right hand originally grasped an imperial standard or staff. It is possible that it was an imperial standard with Christian insignia that was used at the Milvian Bridge.

This unique portrait has many highly distinctive features including a square jaw, projecting dimpled chin, carefully arranged locks, and an aquiline nose. Constantine’s face, which is clean shaven, has a placid expression with large, deeply carved eyes directed towards heaven. The iconography of the portrait, with this upward gaze, possibly in the pose of Jupiter, suggests that Constantine as a rule appointed by God, Constantine as victor or even Constantine as divine. It has been argued that the statue, like the Basilica Nova, was originally made by Maxentius. It has also been argued that Maxentius first reused a second-century colossus, perhaps originally of Hadrian, which Constantine later reworked to resemble himself, just as earlier reliefs were incorporated into Constantine's arch by recutting of the imperial heads.