The Romulan Imperial Guard was the 23rd century military of the Romulan Star Empire in an alternate timeline where Humanity never evolved.
History and specifics[]
In the altered 2260s decade, several ships of the Imperial Guard encountered USS Enterprise and demanded the ship to surrender. The confrontation ended with them being prevented from doing so when the Romulans fell victim to a Klingon spear suicide attack. Captain James T. Kirk remarked that he had never heard of the Romulan military referred to as the Imperial Guard. (TOS novel: First Frontier)