The Romulan Imperial Guard was the military of the Romulan Star Empire in an alternate timeline where Humanity never evolved. Several ships of the Imperial Guard encountered USS Enterprise (NCC-1701) and demanded the ship to surrender but were prevented from doing so by a Klingon Spear suicidal 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)