The Hiram Assembly was an interstellar state that fought againt the Romulan Star Empire in a time before the Earth-Romulan War.

The Hiram initially were winning the conflict and managed to engage the Romulans on the outskirts of the Romii system. However, the Assembly would eventually fall to the Imperial Romulan Fleet with the Hiram colonies being taken over by the Romulans and the species itself rendered extinct. (TOS novel: Captain's Blood)