The first Roman Emperor was Augustus, originally known as Gaius Octavius Thurinus. He came to power after defeating Mark Antony and Cleopatra in 31 BCE, following the turmoil of the Roman Republic's civil wars. In 27 BCE, he was granted the title "Augustus" by the Senate, marking the official end of the Republic and the beginning of the Roman Empire. Augustus implemented numerous reforms, including administrative restructuring and a focus on infrastructure, which contributed to a period of relative peace and prosperity known as the Pax Romana. His reign set the foundation for the imperial system that characterized Rome for centuries.