Probably the most famous Roman ever was Julius Caesar. He was born 150 years before Domitian, in 100 BC, in the time of the Roman Republic.
His full name was Gaius Julius Caesar, and it was his fame and power that caused the name 'Caesar' to be associated with emperors. Over the four hundred years after Julius Caesar's death, there were over sixty emperors, almost all of whom added the name 'Caesar' to their existing name when they became emperor. The German word, 'Kaiser', actually means emperor, and the Russian word for emperor, 'Tsar', also comes from 'Caesar'.
In fact, Julius Caesar was NOT an emperor, because he ruled during the Roman Republic, not the Roman Empire. He was a statesman, and a hugely successful general in the Roman Army. In 55BC, he conquered Gaul, which is roughly the area we now call France (except for one small village, if you believe Asterix and Obelix!). The same year, he invaded Britain. And although the Britons didn't stay conquered on that occasion, Julius Caesar was speaking of his campaigns in Gaul and Britain when he said, "Veni, vidi, vici," or as we still say today, "I came, I saw, I conquered."
In the last few years of his life, Julius Caesar became a dictator, ruling single-handedly over a vast Roman Republic which extended from Spain to Syria. In fact, it was the fact that he made himself dictator for life in the year 44BC that caused the Roman senators to join together and kill him on 15 March, known as the Ides of March.
On this fateful day, Julius Caesar was surrounded by sixty or more senators and stabbed twenty-three times. Only one of the stab wounds was fatal, but it was enough: the great Caesar was dead! The senators who had killed him hoped to restore the Republic to what it had been before Caesar. Instead, it was divided by civil wars, and came to an end less than twenty years later, when it gave way to the Roman Empire.
Julius Caesar. I wouldn't mess with him! Would you?