Sometimes it helps to see the emperors all together or in groups, so here are some visual aids to the emperors of Rome from Augustus to Romulus Augustulus.
This gallery of Roman emperors includes most of the early ones, including the Julio-Claudian emperors (perhaps most famous for Nero and Caligula). It contains a sample from the period after the Flavian Dynasty (the emperors who took possession of Jerusalem and also the emperor notorious for imposing a tax on urine) to the Tetrarchy. It was during this time that the Principate (for princeps, Latin for 'first [among equals]') -- which still tried to maintain at least the illusion of customs from the period of the Roman Republic -- gave way to the far more regal, bureaucratic, and imperious period known as the Dominate (for dominus, Latin for 'lord' or master). During this time the Empire was split into eastern and western sections. The picture gallery also shows some of the main emperors of the Dominate. These pictures come from a variety of sources. Biographies are included following the imperial portraits.