From its completion in 125 A.D. until 1958, the Pantheon's domed ceiling was the largest unsupported concrete span in the world. It was surpassed only with the construction of the CNIT building in Paris.
Everyone in the Middle Ages believed -- as Aristotle had -- that the heart was the seat of intelligence.
At the height of its power, in 400 BC, the Greek city of Sparta had 25,000 citizens and 500,000 slaves.
Emperor Nero's lust for excess was most evident in his elaborate parties. According to the ancient writer Seutonius, Emperor Nero's Domus Aurea had a circular main dining room with a roof that revolved day and night, in time with the sky. In what remains of the palace today, there is a large octagonal room with a domed ceiling that some believe is this dining room. The octagonal room has a large dome with an oculus in the middle. It predates the Pantheon--and was probably the inspiration for it. The architects of the Domus Aurea developed an innovative mechanism cranked by slaves, that made the ceiling underneath this dome revolve like the heavens. While the ceiling revolved, perfume was sprayed from the ceiling and rose petals were dropped on the diners. Legend has it there were so many rose petals falling at one dinner that one of the guests was asphyxiated.
Emperor Trajan, who ruled from 98--117 A.D., was celebrated as the greatest of Roman emperors. In fact, for the rest of Roman history, new emperors were honored by the Roman senate with the prayer felicior Augusto, melior Traiano, meaning "may he be more fortunate than Augustus and better than Trajan." In Dante's Divine Comedy, Trajan is the only emperor allowed into heaven.
For decades after Emperor Nero's death, people all over the Roman empire claimed to have spotted him. Several men even claimed to be him, and started popular movements to be reinstated as emperor. Because of his notoriety and the questionable circumstances under which he died (he purportedly stabbed himself to death in hiding outside of Rome), Nero was the Elvis Presley of ancient Rome.
Many of Rome's most ambitious emperors idolized Alexander the Great. When Julius Caesar was a 33 year-old general in Spain, he wept when he saw a statue of Alexander, lamenting that he had accomplished nothing, while Alexander had conquered the whole world by his age. The schizophrenic emperor Caligula built a bridge of wooden boats across the Bay of Naples and rode back and forth across it on a horse, wearing armor he stole from Alexander's tomb. Emperor Caracalla set out to conquer the same eastern lands Alexander had conquered, and made a great show of visiting his grave in Alexandria, Egypt.
The Colosseum has long been known as a site of Christian martyrdom. It was converted into a shrine as early as the sixth century and still serves as the venue for the Vatican's Good Friday services. However, there is no evidence that Christian persecutions ever took place in the Colosseum.
The Emperor Caracalla--a tyrant remembered for slaying his brother and building the extravagant Baths of Caracalla--was murdered by his own guards while he was relieving himself. That may be where the phrase "caught with your pants down" comes from.