Augustus Caesar (63 B.C.-14 A.D.) - Julius Caesar's grand-nephew and first official emperor of the Roman Empire. He probably never would have achieved that position had it not been for the fact that he was adopted posthumously as Caesar's heir. He was known to be somewhat slight and frail as a youngster and did not succeed on the battlefield the way his great-uncle and so many other powerful Romans at the time had done. A perfect example is when in 46 B.C. he planned to travel with Caesar to Hispania to help quell remaining resistance by Pompey's loyal forces, but fell ill and had to remain in Italy. He did, however, later recover and sailed to the Iberian Peninsula after the campaign was underway. Suetonius records the story that Octavian's ship was wrecked and he had to swim ashore just to survive. He then crossed enemy territory to reach safety. This greatly impressed Caesar and when they returned to Rome, it was at this time that he amended his will to adopt Octavian into his family. After Caesar's death and upon learning of his inheritance, Octavian adopted Caesar's surname and stepped into his role as successor. This was the first wedge driven between him and Marc Antony, who had been Caesar's most prominent general and confidant. In addition, many of Caesar's troops accepted Octavian as his successor, which went a long way toward bestowing on him real power. Despite initial tensions with Antony, the two were allied in hunting down Caesar's assassins. After doing so at the Battle of Philippi, personal ambitions quickly replaced goodwill. Their alliance resulted in the formation of the Second Triumvirate which included Marcus Aemilius Lepidus. It lasted ten years (two five year terms) from 43 to 33 B.C.. While in the triumvirate, they kept up appearances of being friendly towards one another while tensions between them grew. Cicero, who opposed Caesar, publicly threw his support behind Octavian for he feared Antony was the more likely to seize power.
The eventual break between Octavian and Antony is outlined under Marc Antony (see above), so there's no point in rehashing it here. Suffice it to say, their conflict culminated at the Battle of Actium in 31 B.C. (see below). Octavian successfully removed Lepidus from power in 36, and after Antony committed suicide, there was no one left to oppose him. However, he could not simply declare himself emperor. He was a very shrewd politician and used the chaotic situation in Rome to his own advantage. After three civil wars within a 50-year period, the city was in a state of near anarchy, and Octavian was the only Roman in a position to restore order. Despite his ambitions for power, he had a genuine interest in returning the great city of Rome to a state of stability. The senate had become virtually powerless, but to declare himself absolute ruler would not have calmed the waters, and he likely would have ended up like his great-uncle, Julius. 27 B.C. was the key year. Octavian made a public show of returning full authority to the senate; but it was a symbolic gesture and members of the senate knew it. They were aware that he retained the full support of the military and could return Rome to a state of unrest on a whim. So the senate responded by granting Octavian the title of Augustus ("the exalted") and instilling within him control over Rome's civil, religious and military matters; i.e. they made him emperor.
As emperors go, Augustus was very able. His reign finally put an end to Rome's almost constant civil wars and the new empire entered a period known as the "Pax Romana" or Roman peace. With Romans not fighting each other, art and culture began to flourish and Augustus turned his attention outward. He expanded the empire's borders both north and south. Most notably, after Actium, Egypt was annexed. This added a valuable source of grain to the empire. He also made peace with the Parthian Empire which brought stability to the eastern border. Internally, Augustus built roads and bridges making travel throughout the empire easier and set-up a courier system for communication. He standardized the tax system, established a professional military (obviously learning a lesson from past armies pledging allegiance to their commanders), and also commissioned police and fire-fighting forces. He reigned until his death in 14 A.D. at the age of 75. Officially, he died of natural causes; however, there were rumors that he was poisoned by his wife, Livia. His heir was his stepson, Tiberius, Livia's son from a previous marriage.