Julius Caesar's ambition created a colossal empire, and he gave his name to the rulers who succeeded him. He has been a symbol of power and majesty for 2,000 years. But to his countryman, Caesar was an upstart, a gambler and a tyrant who destroyed the Roman Republic and paved the way for the rule of emperors.

Caesar's military brilliance forged a new Rome, but it was Augustus' political genius that made it an empire for the ages. Declared emperor by the Senate, he oversaw a period of growth and prosperity marked by extraordinary artistic achievement and rapid expansion of the empire.

He was seventeen when he took the throne, and during his capricious, fourteen-year rule, Nero almost brought the Empire to ruin. He was unable to quell rebellions and he had many political enemies killed. Eventually, the army rose up against him, the Senate declared him a public enemy and he committed suicide in disgrace.

He overturned centuries-old policies, declaring an end to expansions and abandoning far-flung territories. Hadrian was an enthusiastic patron of the arts, a champion of the common Roman and a tireless diplomat who toured the entire Empire.

Constantine revitalized a fading empire and built a glittering new capital that would stand for over 1,000 years. But his strongest legacy is religious; his conversion to Christianity put an end to hundreds of years of persecution and laid the foundations for Medieval Europe.

He lived more than 500 years after Caesar. He ruled from Constantinople, not Rome. But Justinian restored the Empire to its former glory one last time. He sent his armies west, where they recaptured territory lost to Barbican invasions in the 5th century, reclaiming most of the empire. He is remembered as "the last of the Romans."