Romulans, and their once-mighty Star Empire, have been a Star Trek feature since the early days. Their origins begin on the planet Vulcan, centuries before humanity first ventured outside Earth’s atmosphere.
Before The Time of Awakening, Vulcan was a planet wracked by chaos, suffering, and bloody violence. Most Vulcans felt passionate emotions, made more destructive by their mighty physical strength. Then one person came along: the vaunted Surak. He had a simple idea. Reasoning that what little society Vulcan possessed was being torn apart by these strong emotions, Surak taught one key message… emotional control.
The majority of the population, horrified by the potential destruction of the planet, eventually accepted Surak’s message, but there were some who refused to adhere to the new order. These emotional refugees left the planet, settling towards the distant Beta Quadrant, and calling themselves by a new name – the Romulans.
In Romulan society, emotion is allowed, and this has led to a world similar in organization to Imperial Rome. The Romulan government formed a deep mistrust of anything un-Romulan, and a conquering appetite to put the comparatively puny empire of ancient Rome to shame.
The Federation has had numerous encounters with the Romulans over the years. A small war was fought with antiquated nuclear weapons, and where the combatants could not even see the faces of their enemies. This all changed when Captain James T. Kirk re-contacted the Romulans in the Original Series episode “Balance of Terror”. It soon became clear where the Romulans originated from and that they were a menacing presence on the Federation border.
In The Next Generation, Romulans were a regular feature (and some even defected). Anytime a Romulan Warbird decloaked, you knew the Enterprise-D was in for a rough ride.
But in the later Trek series, the Romulans have suffered disaster, their once mighty Empire collapsing into ruins. They are now reduced to a wandering people with no fixed home.