Final answer:
The sole ruler of Rome in 30 AD was Augustus Caesar, originally named Octavian. He changed his name to 'Augustus' in 27 BCE after defeating his rivals and establishing the Roman Empire, moving away from the Roman Republic's system.
Step-by-step explanation:
Who Became the Sole Ruler of Rome in 30 AD?
The individual who became the sole ruler of Rome in 30 AD was Augustus Caesar, known as Octavian before his rise to power. After Julius Caesar's assassination, Rome was thrown into a period of chaos. Augustus emerged as the successor by defeating his rivals, including Marc Antony, and solidified his power over Rome. To avoid the appearance of monarchy or dictatorship, and in keeping with Roman sentiments against tyranny, Augustus adopted the title of Princeps Civitatis, meaning 'First Citizen' or 'first among citizens' rather than king or emperor.
Name Change and the Founding of the Roman Empire
Augustus was originally named Octavian. Following his rise to power, he was granted the title 'Augustus' by the Senate in 27 BCE, which is a term of reverence meaning 'the illustrious one.' This marked the founding of the Roman Empire and the end of the Roman Republic. The Empire's foundation by Augustus is considered a new chapter in Roman history, deviating from the Republic's emphasis on shared governance and fearing the concentration of power in the hands of a single person.