Augustus constructed numerous public works, among which the following are perhaps the most outstanding: his forum with its temple of Mars the Avenger, the temple of Apollo on the Palatine, and the temple of Jupiter the Thunderer on the Capitoline. Augustus built his forum because the two existing forums could no longer accommodate the increasing number of people and law cases, so that a third was thought necessary. Because of this need for space it was opened for business even before the temple was finished, and it was stipulated that the new forum be the venue for public trials as well as the selection of jurors by lot. He had vowed the temple to Mars during the battle at Philippi, which he fought to avenge the death of his father Julius Caesar. He decreed, therefore, that the Senate use the forum to deliberate on war and the awarding of triumphs, that those heading off to provinces with military command be officially escorted from here, and that those who returned victorious should deposit the insignia of their triumphs in his forum.