The Temple of Mars Ultor, the Avenger. Vowed by Augustus at the battle of Philippi, B.C. 42, and erected by him in the centre of his new forum.

Three beautiful pillars, and part of the wall of the cella and of the roof of the vestibule, still exist near the Arco dei Pantani, which owes its medieval name to the marshes caused by the water collecting in this neighbourhood. They stand upon a substruction only excavated a few years ago, and present one of the finest specimens extant of a temple, all the essential parts of which have been preserved. The gigantic walls of rectangular blocks of tufa, into which the travertine arch already mentioned was introduced for the purpose of forming a communication with the other part of the city, are most imposing, and formed part of the second wall of Rome and the boundary of the Forum of Augustus.

"The Temple of Mars was built in fulfillment of a vow made during the war of Philippi, undertaken by him to avenge his (adopted) father's murder. He ordained that the senate should always assemble there when they met to deliberate respecting wars and triumphs; that thence should be dispatched all those who were sent into the provinces in the command of armies; and that in it those who returned victorious from the wars should lodge the trophies of their triumphs" (Suetonius, "Augustus," xxix.).

"The Emperor August, being consul with Caninius Gallus. gratified the eyes and minds of the Roman people, on the occasion of dedicating the Temple to Mars, with the most magnificent spectacles of gladiators and a sea-fight" (Velleius Paterculus, ii. 100).

By entering the stonemason's yard, opposite the temple, we can see the travertine niches built by Augustus up against the wall of the kings, to receive the statues which he put up in the porticoes.

S. Russell Forbes, Rambles in Rome: An Archaeological and Historical Guide to the Museums (London, Edinburgh, and New York: Thomas Nelson and Sons, 1882), 200-201.