Augustus was never officially named emperor of Rome, but was made president of the senate and Pontifex Maximus, or chief priest. He co-led with Mark Antony and Lepidus, who was Pontifex Maximus before Augustus, in what was referred to as a triumvirate. This arrangement was set to last for 5 years, but was renewed several times, until Mark Antony's plans to move the capital of Rome to Alexandria were revealed.
The battle between Augustus and Antony led to Antony committing suicide, and Cleopatra followed shortly after. It was soon after this that Augustus earned the title of President. He had numerous other successes following the defeat of Mark Antony, but his main focus after this was setting up an heir to take over for him.