Roman arches were constructed for purpose of announcing and commemorating a victory in a major military conflict. For six hundred years they were the ways and means to bring the victory back to the Roman people. But their original purpose began to shift along with the very fabric of authority in Rome.
Celebrating a Major Victory: During the republic era, after a major military victory when the army returned to Rome a lavish celebratory parade paid for by the Senate would be held to honor the victorious general publicly. Typically, the procession would begin by entering the city through the porta triumphalis, portal of triumph, through the wall that surrounded the city. By entering the city, the general’s mandate and authority from the Senate to conduct the military campaign ended. Tradition led to passing through the portal as a symbolic measure to honor the victor and indicate that the conflict was over. The parade began with members of the Senate riding in chariots followed by more chariots displaying the spoils of the war. This could include treasure as well as unusual weapons or contraband, and prisoners of war in chains. Then the victorious general would enter standing in his chariot. The celebration did not always end with the parade, as there were banquets, games, and other festivities that could go for several days. The victorious general became a triumphator, and often would build an arch of his own complete with statues that honored the victory. These arches were of a temporary nature made largely of wood, and none of them from the republican era survived, including the portal of triumph through the wall.
Focus During the Imperial Period: When Augustus reigned and ushered in the imperial era, the concept of celebrations of triumph changed. As supreme leader, Augustus commanded all the generals and was the only individual that could provide a mandate for a general to conduct a campaign. Subsequently, this brought an end to individual generals creating their own monuments to themselves, and shifted the glory toward the emperor. It also led to more permanent arches being constructed with more elaborate decorations commemorating the military victory, but glorifying the emperor more than the victorious general. Although usually pertaining to military victories, these arches later became more of a political propaganda device, relaying the power and authority of the emperor as the ultimate ruler. They were often set over roads or streets in areas that required them to be passed through and not around. In addition to praising the military victory, the inside of the arch would display inscriptions and ornamentation reminding the viewer of the authority and reach of the emperor, and the laws of the state. The materials used in building the more permanent arches differed but usually consisted of travertine and marble mixed with concrete and brick. They were made up of finely cut, often gilded, letters that were designed for maximum simplicity and clarity. This fundamental form of typography can be found today especially in advertising, or public signage.
An Important Source of Information: During the fourth century A.D. Rome had a total of thirty-six permanent arches. Today, there are only three: the Arch of Titus, the Arch of Septimius Severus, and the Arch of Constantine. Scholars have been able to learn about those arches that didn’t survive from the writings of some of the well-known authors of the day. With their texts they gave us in modern times an insight of the battles, the victories, the celebration, and the propaganda provided by arches. Emperor Domitian commissioned the Arch of Titus in A.D. 81 in honor of his brother Titus, who led the capture of Jerusalem in 70 C.E. Titus became emperor and ruled Rome after his father Vespasian and before his younger brother Domitian. The Arch of Septimius Severus was dedicated in 203 A.D. to commemorate the Roman victory over the Parthians in Arabia and Assyria. Its design consisted of three arches: the main one in the center accompanied on each side by a smaller arch. The Senate commissioned the Arch of Constantine to commemorate his victory over then Emperor Maxentius in the Battle of the Milvian Bridge over the Tiber River in A.D. 312. Located near the coliseum, the Arch of Constantine spans the original route of the Triumphalis.
Other Than Military Victories: The more permanent arches of the Imperial Era included several that did not specifically commemorate a military victory. There were arches built to commemorate the completion of roadways, or the expansion of port facilities. Other arches were built in various parts of the empire such as Tarragona, Spain to honor Augustus, and Tripoli in North Africa to honor Marcus Aurelius. A four-sided arch was built to honor Septimius Severus in his birthplace, Leptis Magna in what is modern day Libya. The concept has been retained in more modern times with Napoleon’s Arc de Triomphe in Paris.
Conclusions: The Roman arch was built originally to honor the victors in a major war. But as time went on and the republic gave way to the empire, the purpose and value of the arch morphed into a sign post along the road or path that served to remind those who passed through of the power and authority of the Roman emperor.
Sources:
National Geographic History, Volume 10 Number 6, Triumphal Arches of Rome, January/February 2025.
Wikipedia, Ancient Roman Architecture.
Wikipedia, Arch of Constantine.