Sle'Stacheyar
A race of hostile aliens never seen by a citizen of the Empire. The Sle'Stacheyar were discovered during an exploratory mission of the Imperial Expeditionary Force. Jugding by pictograms discovered at several abandoned Sle'Stacheyar colonise, Imperial scientists determined that the aliens were a race of highly advanced creaturse with similar scientific and social abilities. After first contact with the Imperial Expeditionary Force, Emperor Torindine determined that the aliens posed a potential threat to the safety of the nearest system -- Gerbanon. He ordered the destruction of any non-Imperial vessel found near Gerbanon. This led to the Border Skirmishes, the Insect War, and ultimately the launching of the Death's Head Missile by the enemy.