The Chodak Empire was an interstellar entity that controlled a vast area of the Milky Way Galaxy approximately 100,000 years before the modern era. The was centered on what would eventually be known as the Romulan Neutral Zone. The civilization eventually declined, and left behind relics on many worlds.
By the 24th century the Chodak species was considered extinct, yet their descendants actually survived in the Beta Quadrant, on the far side of the Romulan Star Empire. They reemerged as a minor power circa 2370. (TNG video game: A Final Unity)