After Octavian had defeated Egypt, he had a choice to make. If he resigned, civil war would return; if he became absolutely powerful, as he thought was best, he would be despised and would probably come to a similar end as Caesar did. So what did he do?
Octavian realized that he needed to win over the public and the senate, so he distributed the plunder gotten from Egypt to the citizens of Rome. He also pardoned landowners their tax debts. He came to the senate and relinquished the powers given to him to protect Rome. The senate, much impressed by this act of ”selflessness,” promptly bestowed them back upon him.
He continued as consul, and accepted administrations in Gaul, Spain, and Syria (where most of his legions were), along with miscellaneous other honors. When given the title ”Augustus,” meaning ”revered one” and reserved for very special places or things, he modestly preferred the title ”Princeps,” meaning ”first citizen” (although everyone knows him today as Augustus). After resigning his consulship, he received an imperium that could override any provincial governor. This he used tactfully so that people would not think he had too much power. He also received a tribunicia protestas-power of a tribune- which gave him civil authority in addition to his military authority and the foreign authority from his imperium.
Octavian had successfully acquired civil, military, and provincial power right under the noses of the senate and the Roman public. By keeping the exterior similar to the old republic, he was able to completely change the inner workings of the government from a republic to an empire without anybody noticing.