it was the general irresistible tendency toward emperor-worship which kept it alive and made it the model for a tremendous subsequent development.  Augustus had accomplished his desire.  Men were looking on Caesar as a success after all and not as a failure.  The Di Manes of a murdered emperor had been profitably exchanged for the Divus Julius, and just as the gods had founded the old Rome of Romulus, so again it was a god who had laid the foundations of the empire over which his successor was ruling.

But Augustus was not content with this; it was all very well for men to look upon the god Caesar as an illustration of justification after death, as an example of how heaven could right the wrongs of earthly existence, but that was not sufficient; the punishment of those who caused his earthly downfall must be emphasised, it must be shown that the gods were quite as much interested in punishing the sinner as in rewarding the righteous man who was sinned against.  It was one thing to transfer one’s ancestors to the gods, it was quite another thing to take measures to keep oneself from following in their footsteps, even though their last estate was theoretically desirable.  Hence side by side with the cult of the Divus Julius went that of Mars Ultor, Mars the Avenger.  The circumstances of the beginning of the cult show that it was no mere poetical title but a genuine cult-name born in an earnest moment:  for the great temple subsequently built to Mars under this cognomen was vowed by Augustus “in behalf of vengeance for his father,” in the war against the slayers of Caesar, Brutus and Cassius.  This temple, vowed at Philippi in B.C. 42, was so slow in building that in the meantime Augustus erected a small round temple to Mars Ultor on the Capitoline.  This was dedicated May 12, B.C. 20.  In the years which followed Augustus proceeded with the difficult and extremely expensive task of purchasing property for his own Forum, and here was built and dedicated, August 1, B.C. 2, the great temple of Mars Ultor.  But aside from being a very present reminder of the vengeance which the gods had in store for those who killed a Caesar, it stood also for the Julian house, for Mars was not alone in the temple but with him was Venus, the ancestral mother of the family of Julius and Augustus; and thus was once more emphasised the connexion between the ancestors of the ruling house and the great ancestor Mars, from whom all Romans were sprung.

A temple possessed of such strong associations with the imperial family became instantly a centre of their family worship, and in this respect produced another rival to the cult of Juppiter on the Capitoline.  In connexion namely with the putting on of the toga virilis the members of the imperial family went to the temple of Mars Ultor instead of following the immemorial custom of ascending the Capitol to the shrine of Juppiter Optimus Maximus.  More important yet the insignia of the triumph, which had always been in the keeping of the Capitoline Juppiter even before he was Optimus Maximus and while he was only the “Striker,” Feretrius, were now preserved in the temple of Mars Ultor.