The Romulan Empire

The Romulans are a Alpha Quadrant humanoid race that originated from dissident Vulcans that rejected the teachings and philosophy of peace and logic of the legendary Vulcan philosopher Surak (the father of the modern Vulcan civilization). They settled on the planets of Romulus and Remus, enslaving the native Remans in the process. The development of warp drive enabled the Romulans to expand their territory into a empire known as the Romulan Star Empire. 

The Romulans are known for their xenophobic character and policies of extreme secrecy, subterfuge and territorial expansionism. By the end of the 23rd century, the Romulans were counted among the most powerful races in the Star Trek Universe.