For now you understand, Romans ruled the land, and the name of the Emperor was... CAESAR AUGUSTUS! CAESAR AUGUSTUS! CAESAR AUGUSTUS! How many people in this land? How many people in this land? I want to do a census! (He wants to do a census!) I want to do a census of the people in this land. What's a census? (What's a census?) It's a countup of the people in this land.
~ - Popular song describing the Roman's rise to power
Much like the Black Legend, the Romans have been shown as a people bent on world domination in many depictions of History, most notably in The Bible.
The Romans were under many different Emperors and sought to conquer the world. They wanted to rule Britain and expand their rule far beyond the ancient Egyptians. They had horrific methods of killing their enemies, the most famous of course is crucifixion.
The Romans were also bloodthirsty and liked wars. Their nobility also practiced the arts of incest, believing their status to be divine and believing they had the right of incest.
The Romans appear notably in the New Testament, having conquered Israel in 63 BC and having been planning their rule for quite some time ever since 53 BC. By the year 28 AD, the Romans were supremely dominant in Israel and much of the Middle East.
Much of Roman culture was linked to business, trade and commerce - much of these are now seen as the root of all evil today. The Romans were all about money and climbing the social ladder.
Also, the Romans are seen as evil because they did not recognize Jesus as divine and rejected him completely with only 2 casual mentions of him in the Bible. Even after crucifying him they did not see him as special. However, after the earthquake that hit Jerusalem after crucifying Jesus, the Romans began to doubt their faith and started seeing that Jesus was indeed divine. This led to them slowly embracing Christianity, especially under the reign of Constantine the Great, who had himself baptised before his death to wash away his sins. The years following Constantine's reign would see Christianity becoming the official state religion of the Roman Empire.