The Supreme Commander of the Romulan Military is officially the Emperor. However, the Emperor rarely directly commands the military forces of the empire personally these days, as the Imperial Office is generally forced to focus on internal affairs, such as economic security and logistical problems within the Romulan Star Empire.
Because of the huge number of duties given to the Emperor, the Imperial Consul of War is charged with leading the Romulan Military in the Emperor's stead. The Consul of War then appoints the Council of War from members of the Military Meritocracy (Generally Navy Admirals, Tal Shiar Colonels and Legion Legates of the Romulan Army). The Council of War then is employed as an advisory board to the Consul of War, and with the Council's help determine Romulan Military Policies.
ROMULAN STAR NAVY
The highest rank within the Romulan Star Navy is that of Fleet Praetor, who commands one of the five primary Romulan
Imperial Fleets. Each of these fleets is then divided into five
Sector Fleets, which are commanded by an Admiral. Each Sector Fleet is divided into four to ten sub-fleets called
Battle Fleets. Battle Fleets are led by Vice Admirals, and divided into varying numbers of
Task Forces commanded by a Rear Admiral, which include a varying number of starships, generally given to a Commander. The intraship rank system for commissioned officers is as follows: Commander, Subcommander, Centurion, Lieutenant, Sublieutenant and Ensignant.
TAL SHIAR
The Tal Shiar is the Romulan Intelligence Service, and is without a doubt the most brutal and unforgiving organisation in the empire. The Tal Shiar maintains hundreds, if not thousands, of listening posts in (and outside of) Romulan Space, listening not only to foreign governments, but to imperial citizens as well. They are tasked with maintaining and ensuring loyalty to the Emperor and the Senate, and will stop and nothing to achieve their goals. They have practically limitless jurisdiction within the Empire, and often just the threat of turning a captured prisoner over to the Tal Shiar will make them confess. Their ranking system is as follows: General, Colonel, Captain, Major, Lieutenant, Sublieutenant, Polisium, Subpolisium, Inspector, Subversive, Informant, Recruit.
ROMULAN ARMY
The Romulan Army is the ground component of the Romulan Military, and is generally very effective at conducting efficient operations with very little notice or support. They also defend and patrol the cities and worlds of the empire, under Tal Shiar commanders. The Army ranking system is as follows: Imperial Legate, Legion Legate, Legate, Sublegate, Prefect, Full Centurion, Centurion, Subcenturion.