The Ara Pacis Augustae (Latin, "Altar of Augustan Peace"; commonly shortened to Ara Pacis) is an altar in Rome dedicated to Pax, the Roman goddess of Peace. The monument was commissioned by the Roman Senate on July 4th 13 B.C. to honor the return of Augustus to Rome after his three years in Hispania and Gaul, and consecrated on January 30th 9 BC by the Senate in celebration of the peace brought to the Roman Empire by Augustus' military victories. The altar was meant to be a vision of the Roman civil religion.
It is made up of a small functional altar at its center, and four surrounding walls; externally, two-tier friezes run along the walls and portray the peace and fertile prosperity enjoyed as a result of the peace brought to Rome by Augustus' military supremacy (Latin: Pax Augusta). The Altar was built to remind Romans, through a visual medium, of the competence and achievements of the Julio-Claudian dynasty. The sculpture on the outside of the monument emphasise the importance of piety (pietas) and peace within the empire.
The Altar was originally located on the northern outskirts of Rome, a Roman mile from the boundary of the pomerium on the west side of the Via Flaminia. It stood in the northeastern corner of the Campus Martius-a formerly open area that Augustus developed as a complex of monuments-and on the flood plain of the river Tiber, where (starting from the second century AD when the Altar was protected by a wall) it gradually became buried under four meters of silt over the centuries. The Ara Pacis was substantively rediscovered in the twentieth century, and moved to its current location in 1937–8.