View looking north at the north end of the Forum of Augustus at the Temple of Mars Ultor (the "Avenger"). The stairs on the left, sheathed in white Italian (Luna) marble, lead up to the pronaos where four of the original eight Corinthian columns have been reconstructed. The cella (cult room) of the temple butted up against the high back wall, and the outline of its roof can be seen in the wall.
Three original Corinthian capitals still stand, along with the lintel that they supported. The gate on the right, with steps leading up to it, opened into the Subura, a very crowded area north of the Forum. On the dark grey tufa walls, note the horizontal white strip of travertine marble. This sturdy back wall was constructed to protect the forum in case a fire broke out in the suburb to the north of it!.
This temple was built in fulfillment of a vow that Octavian (later "Augustus") made before winning the battle of Philippi in 42 B.C.—where he defeated the assassins of his "father" Caesar.