"All right... all right... but apart from better sanitation and medicine and education and irrigation and public health and roads and a freshwater system and baths and public order... what have the Romans done for us?"- John Cleese
The Roman Empire existed for over a thousand years and started about 2,300 years ago (in western part of the Empire it ended in 476 CE but persisted in eastern part, later Byzantium, until 1453. The Roman Empire was centred round the Mediterranean region in Europe, western Asia and North Africa. Its northernmost outpost was Britannia, now southern Britain. The northern limit was usually Hadrian’s Wall (though it sometimes went further). Its eastern limit was usually in eastern Syria and Anatolia and Armenia where it bordered and frequently clashed with the rival Parthian Empire. In the 19th Century the British Empire also involved exploitation as does United States Imperialism today.
The Roman Empire was based on Militarism, Slavery, extreme cruelty and exploitation of subjugated people's - something of a neocon wet dream. Romans crucified Jesus according to the Bible. Anti-semites like to blame Jews for the crucifixion though Romans did it.
The early Romans had a republic. It was not a democratic republic. The nobility or Patricians ruled though the Senate. Later the lower class Romans or Plebeians had a right of veto. Later still Rome and its empire were ruled through the emperor who was a monarch, purple was the imperial colour. At some times in history there was one emperor. At other times there were more than one emperor who could be at war or at peace with each other.
Romans spoke Latin.
Religion of the Roman Empire
The Roman empire was large and diverse and many different religions were there. The Greeks and Romans worshiped a pantheon of imaginary gods and goddesses, see Similarities between Roman, Greek, and Etruscan mythologies. Different people from different parts of the Roman Empire learned the superstitions that other communities in the Roman Empire followed. so people in the Roman Empire adapted each other's superstitions and developed new superstitions that combined ideas from different sources. The New Age movement today is a bit similar.
As Pantheists the early Romans were a pretty tolerant lot when it came to Religion, in distant lands people might know the gods by different names but provided they were happy to add Roman Emperors to their gods there was no need for conflict. As they came up against monotheistic religions that disrespected the Gods there was more of a problem. The later Roman Empire itself became Christian and did much to twist the teachings of Jesus from something suitable for a bunch of sandal wearing hippies and made it into something more appropriate for an Imperialistic society based on greed and violence.
Christianity started in the Roman Empire but it is no more reasonable than The Greeko-Roman religion or any other religion. Unfortunates those who've been Taught to believe Christianity from early childhood can't always see that.