Altar of Domitius Ahenobarbus

Location	Field of Mars [1]
Built in	Between 122 and 115 BC
Built by/for	Cn. Domitius Ahenobarbus
Type of structure	bas-relief
Related	List of ancient monuments in Rome

The Altar of Domitius Ahenobarbus, more properly called the Statuary group base of Domitius Ahenobarbus, is a series of four sculpted marble plaques which probably decorated a base which supported cult statues in the cella of a Temple of Neptune located in Rome on the Field of Mars.

The frieze is dated to the end of the second century BC, which makes it the second oldest Roman bas-relief currently known. However, there is also a contemporaneous relief depicting a Roman naval bireme with armed marines,from a temple of Palastrina built c. 120 BC.

The sculpted panels are still visible today, with one portion on display at the Louvre (Ma 975) and another at the Glyptothek in Munich (Inv. 239). A copy of this second piece can be seen at the Pushkin Museum in Moscow.

The base was found in the Temple of Neptune built near the Circus Flaminius, by the Field of Mars. Remains of this temple may have recently been discovered under the church of Santa Maria in Poblicolis, but their identification remains uncertain.

The reliefs seem to have been produced during the construction of a Temple of Neptune on the Field of Mars. A general, probably Cn. Domitius Ahenobarbus, vowed to build a temple for the god of the sea after a naval victory, perhaps the one won off Samos in 129 or 128 against Aristonicus who had attempted to oppose the donation of Pergamon to Rome by the will of King Attalos III. The construction of the temple (or restoration of a pre-existing temple) only dates to 122 BC, the year in which Cn. Domitius Ahenobarbus attained the consulship.

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