Answer:
Caesar Augustus
Explanation:
Octavian in 29 BC declared himself Roman emperor, assuming the name of Caesar Augustus. Under his rule, the Roman Empire became an austere and centrally controlled monarchy. With it, also the Latin language and the Roman alphabet became standard for the whole Europe. Although Rome was already an empire before Octavian became Caesar Augustus, it fell to him to proclaim "the" Roman Empire. He was also the one who ruled during the period when Pax Romana (the peace of Rome) reigned over the whole "known world."
