The Arch of Constantine is a triumphal arch

Triumphal arch

A triumphal arch is a monumental structure in the shape of an archway with one or more arched passageways, often designed to span a road. In its simplest form a triumphal arch consists of two massive piers connected by an arch, crowned with a flat entablature or attic on which a statue might be...

 in Rome

Rome

Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...

, situated between the Colosseum

Colosseum

The Colosseum, or the Coliseum, originally the Flavian Amphitheatre , is an elliptical amphitheatre in the centre of the city of Rome, Italy, the largest ever built in the Roman Empire...

 and the Palatine Hill

Palatine Hill

The Palatine Hill is the centermost of the Seven Hills of Rome and is one of the most ancient parts of the city...

. It was erected to commemorate Constantine I

Constantine I

Constantine the Great , also known as Constantine I or Saint Constantine, was Roman Emperor from 306 to 337. Well known for being the first Roman emperor to convert to Christianity, Constantine and co-Emperor Licinius issued the Edict of Milan in 313, which proclaimed religious tolerance of all...

's victory over Maxentius

Maxentius

Maxentius was a Roman Emperor from 306 to 312. He was the son of former Emperor Maximian, and the son-in-law of Emperor Galerius.-Birth and early life:Maxentius' exact date of birth is unknown; it was probably around 278...

 at the Battle of Milvian Bridge

Battle of Milvian Bridge

The Battle of the Milvian Bridge took place between the Roman Emperors Constantine I and Maxentius on 28 October 312. It takes its name from the Milvian Bridge, an important route over the Tiber. Constantine won the battle and started on the path that led him to end the Tetrarchy and become the...

 on October 28, 312. Dedicated in 315

315

Year 315 was a common year starting on Saturday of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantinus and Licinianus...

, it is the latest of the existing triumphal arches in Rome, from which it differs by spolia

Spolia

Spolia is a modern art-historical term used to describe the re-use of earlier building material or decorative sculpture on new monuments...

, the extensive re-use of parts of earlier buildings.
The arch is 21 m high, 25.9 m wide and 7.4 m deep. It has three archways, the central one being 11.5 m high and 6.5 m wide, the lateral archways 7.4 m by 3.4 m each.