Forum of Augustus
The second of the imperial fora, built to rival that of Julius, the Forum of Augustus and its Temple of Mars Ultor (the Avenger) were vowed by Octavian on the eve of the battle of Philippi (42 BC), where he avenged the assassination of Caesar, his adoptive father. Having consolidated his power and then completed the building projects initiated by Caesar, it may not have been until 20 BC, when Augustus negotiated the return of military standards lost by Marcus Crassus to the Parthians (and so avenged Rome a second time), that work on the temple actually began (Dio, LIV.8.3). Or it may have been later still, in 17 BC, when Augustus, having "commanded those who celebrated triumphs to erect out of their spoils some monument to commemorate their deeds" (Dio, LIV.18.2), set the example, himself. The site was on private property and had to be purchased ex manubiis, that is, from the spoils of war in Spain and Germany, Dalmatia and Egypt. Augustus, in the Res Gestae (XXI), relates the cost to have been a hundred million sesterces. Even then, not all the land could be acquired. There also were architectural delays (Macrobius, II.4.9), and the temple still was unfinished when the forum was dedicated on 2 BC.
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