This Roman leader, who never called himself a king or emperor but preferred First Citizen of the State, was part of the Second Triumvirate in 43 BCE. After his adopted great-uncle's murder, he consolidated power by removing Lepidus and Mark Antony by 27 BCE. He ruled Rome until his death in 14 CE, ushering in a period of peace known as Pax Romana. For 10 points, name this Roman leader succeeded by Tiberius in 27 CE.
a) Julius Caesar
b) Augustus
c) Nero
d) Marcus Aurelius