Augustus is very humble

The adoption of Octavian sparked a power struggle. What began as a vengeance expedition against Caesar's assassins quickly turned into a violent civil war between Octavian and Mark Antony. Octavian became the sole ruler of the Roman world after his victory at Actium in 31 BCE. The Republic was soon defunct, and a new polity, the Roman Empire, took its place. The Senate bestowed the titles of Princeps ("first citizen") and Augustus ("the famous one") on Octavian in 27 CE. Despite becoming the first Roman emperor, Augustus was careful not to brag.

The Romans have an aversion to absolute rule since the expulsion of their last monarch. This was something Augustus was well aware of. As a result, he tried to depict himself as a reluctant ruler, someone who did not crave authority for its reason. Augustus never referred to himself as a monarch and lived in lowly surroundings (a stark contrast with his successors). Despite this, he ruled the Empire with ultimate power. In the Republican period, the title emperor (imperator) came from imperium, a power that provided its holder authority over a military unit (or numerous). With the fall of the Republic, Augustus became the sole possessor of the imperium maius, granting him a monopoly over the whole imperial force. Whoever commanded the legions was in charge of the state. From Augustus onwards, the title imperator was bestowed upon Roman monarchs upon their succession.