The Arch of Constantine is the largest of the three triumphal arches still preserved in Rome, about 25 meters high, located along the road usually used by the triumphs, in the stretch between the Circus Maximus and the Arch of Titus.
The arch was erected in 315 to celebrate the victory of Emperor Constantine over Maxentius, which took place on 28 October 312 AD in the battle of Ponte Milvio. It was built by partially reusing materials and architectural elements from more ancient imperial monuments, belonging to the age of Trajan, Hadrian and Marcus Aurelius.
All the faces of the emperors in the reliefs were remodelled in the likeness of Constantine, with the nimbus to remark his imperial majesty.
It is probably to be considered as the first example of that systematic reuse of the material, lasted throughout the Middle Ages and, at the same time, represents a precious synthesis of over two centuries of official Roman art.
It has three arches: the central one is the widest and has a rich bas-relief decoration on all its sides. The exploits of Constantine in his campaign against Maxentius are depicted above the minor arches. Higher up, scenes of hunting and sacrifices are depicted in the tondos of the Hadrian age.
In the attic, eight statues of Dacians stand out, coming from the Trajan's Forum, flanking the long inscription and large panels of the Marcus Aurelius period, with episodes from the Germanic war. The bases of the Corinthian columns are decorated with allegorical figures.
The monument, included in the mid-twelfth century in the Frangipane fortress, underwent renovations starting from the end of the 15th century and throughout the 16th century and then in 1733, when extensive additions were made to the missing parts.
Near the arch are the remains of the so-called Meta Sudans, a monumental fountain built in the Flavian age. The name "meta" derives from the conical shape that remembered a sort of column of the ancient Roman circus, while "sudans" indicated the water that gushed out of it.
The fountain remained in use until the 5th century AD when the laying of the Colosseum Valley began to obstruct the water outflow canals. In 1933, during the fascist era, the ruins were then demolished to create via dei Trionfi.