The Temple of Venus Genetrix. September 26, 46 BC.

The night before the battle of Pharsalus (48 B.C.), Julius Caesar (100-44 B.C.) vowed a temple to Venus Genetrix (“Mother Venus”), mother of Aeneas, and the mythical ancestress of the Julian family. The Temple was dedicated on 26 September 46 BC, the last day of Caesar’s triumph.

“…and vowed, if he was successful, to make a thank-offering by building a temple to her in Rome as bringer of victory.”

Appian, The Civil Wars (II.68)

The Forum of Julius Caesar, in which the temple stands, was finished by Augustus (63 B.C.-A.D. 14) in 29 B.C. The cult statue was sculpted for Caesar by Arcesilas, and there were other statues and precious objects on display here. Trajan (A.D. 53-117) rebuilt the temple, which also had to be restored after the fire of A.D. 283. On this occasion, the front porch was enclosed in a brick wall, giving the façade its (for a temple) strange appearance.
The temple was built of brick faced with marble and had eight columns (octastyle) on the facade, and also eight columns on each side. The ceiling of the temple was vaulted. There were some nontraditional elements in the design of the temple such as the height of the podium it sat upon and the method of accessing it.

“Access to the cella was afforded by circulation through the flanking arches, up narrow stairs on either side, to a landing in front of the temple, from which several more steps extending the width of the facade conducted to the cella level.”

Grossi, Olindo (1936). “The Forum of Julius Caesar and the Temple of Venus Genetrix”. American Academy in Rome.

It was placed at the far end of the court enclosed by the Forum, a practice that was borrowed by the Romans from the Etruscans and which later became a standard architectural feature throughout the Roman Empire. The Temple sat embedded in the remaining slope that had been cleared away from the Capitoline Hill.
The Temple was styled in Corinthian order. This included carved mouldings, capitals, and entablature. One of the mouldings, the cyma moulding, has carved dolphins, shells, and tridents. These particular symbols refer to Venus and the sea.
Items found inside the Temple include a statue of Venus by Arcesilas as well as statues of Julius Caesar. Numerous Greek paintings by Timomachus of Ajax and Medea, six collections of engraved gems, a breastplate decorated with pearls from Britannia, and a controversial golden statue of Cleopatra as the goddess Isis once filled the Temple.
All of these treasures are now long vanished. In front of the temple stood three fountain basins which were set at either end of the facade. A low wall ran between them.
The remains of the Temple of Venus Genetrix have survived, along with the structure’s three sides, engravings and die-punched spirals.