Augustus - the first Emperor of Rome
Octavian, later taking the name of Augustus, was the adoptive son of Julius Caesar. Augustus' s political ambition came to the fore after the assassination of his adoptive father in 44BC. He ended a century of civil war and became sole ruler, thereby establishing the julio-claudian dynasty and empire. Although officially attempting to restore the republic (restitutio rei publicae), Augustus did in fact affect its permanent change into a monarchy in the form of a principate.