Emperor - The Head of State of the Galactic Empire.
Imperial Executor - Assistant to the Emperor, Overseer of the Imperial Military.
Grand Vizier - Right hand to the Emperor, Overseer of the Imperial Throne and Goverment.
Grand Moff - Head of the Imperial Goverment.
Grand General - Head of the Imperial Military.
Grand Admiral - Head of the Imperial Navy.
Commandant - Head of the Officer Academy.