Augustus did a number of things to help the Roman Empire succeed.
First, he took power over the empire as a whole after the civil war that followed the assassination of Julius Caesar.
Second, he did some things to expand the empire. He finalized the conquest of Spain. He set up client kingdoms in the east of the empire so that the Roman army itself would not have to defend such a large area. He instituted reforms in the army that helped make it stronger.
Finally, Augustus put forward changes in society that helped to keep Rome stable. Most importantly, Augustus brought back an emphasis on religion. He felt that religion would help to bind the people together and keep the empire more stable. Therefore, he restored old religious rituals and buildings and also created a new imperial cult. These helped to make the empire more stable.
The time Augustus took over the leadership of the Roman Empire is considered a time of growth in spite of the different internal challenges that threatened the stability of the empire. The civil war after the assassination of his uncle Julius Caesar and the threat posed by Brutus and his accomplices were some of the major challenges. Augustus was however successful in holding the vast empire together during these tumultuous times and ensured continued stability by instituting restructuring reforms within the administration. He changed some aspects of the military, and introduced new provinces to improve administrative efficiency. He further categorized these provinces into those administered by the emperor and those administered by the senate. He ensured that his position did not alienate him from the people by symbolically preferring to be referred to as “first among equals” and not the term “emperor” which otherwise seemed distant to the citizenry. He reduced the number of soldiers in his armies but increased their pay. This strategy worked well because the soldiers were content and this boosted their motivation leading to much success in the empire’s expansion efforts.