Navis Imperialis - Commissioned Officers: Commissioned officers represent the highest ranks of the Imperial Navy personnel and their commissions usually can only be granted by the Battlefleet Administratum.Lord High Admiral of the Navy - A Lord High Admiral (also referred to as a Lord Militant Commander or Lord Commander) is the senior-most command rank within the Imperial Navy. The prior position held by most of these supreme naval commanders was Lord High Admiral of the Segmentum Solar. The Lord High Admiral of the Navy oversees the Imperial Navy's interests on the Senatorum Imperialis on Terra, while the five Segmentum Lord High Admirals manage the fleet affairs of their Segmentum Battlefleets.Lord High Admiral - Also called a Battlefleet Commander, Lord High Admiral is the highest commanding rank of the Imperial Navy. Only five of these august individuals exist, one for each of the Segmentae Majoris. Each is responsible for the Imperial Navy's fighting forces across thousands of sectors in their allotted portion of the galaxy, or in the case of the Lord High Admiral Solar, the substantial volumes of space around Terra itself.Lord Admiral - A Lord Admiral, or Sector Commander, is responsible for all naval operations in a given sector and has direct command of units of the Segmentum battlefleet allocated to that sector.Solar Admiral - Solar Admirals are often prospective sector commanders waiting for assignment to a sector. As such opportunities are rare, it is far more common for Solar Admirals to be dispatched to warzones in command of a reinforcing fleet or kept busy on "special duties" with their own independent flotilla.Admiral - An Admiral is allocated command of a portion of a sector's fleet and responsibility for the security of a handful of star systems and the vast tracts of wilderness space that lies in-between.Vice Admiral - By long tradition, a Vice Admiral commands the leading division of a fleet, the part that would equate to the vanguard of a terrestrial force. In later times this has come to mean commanding a force of Light Cruisers and Destroyers charged with scouting for the enemy, charting navigational hazards and long-range patrolling.Rear Admiral - In ancient times when an entire Battlefleet might be massed together, the thousands of starships present would be divided into three commands, each under the command of their own Admiral. The Rear Admiral was the youngest and least experienced flag officer in the fleet and so would be given charge of the rearmost division as the one least likely to see combat. Over time this flag rank has evolved into a largely administrative post charged with coordinating repair facilities, refuelling ships, forming convoys and other rear echelon activities. Time spent as a Rear-Admiral is seen as essential for a flag officer who aspires to higher ranks to demonstrate their facility with logistics and high-level planning.Commodore - Also sometimes called a Group Commander, the rank of Commodore was originally only a temporary one given to a senior Captain placed in charge of a squadron of starships. Over time the rank of Commodore has found its way into permanent usage as what were once temporary squadrons stabilised into regular patrol routes and areas of responsibility. On rare and terrible occasions when capital ships join together in squadrons the senior Captain is still promoted to Commodore for the duration of the engagement.Lord Captain - Sometimes also referred to as Flag Captain, Lord Captain is an honourific rank normally applied to Captains who command vessels on detached duty.Captain - Imperial Navy Captains are the masters of all that they survey. Aloof and uncompromising, these figures are unbowed by the awesome responsibility entrusted to them. These exceptional individuals hold full command of an Imperial Navy warship and all the souls that reside within it.Commander - A Commander is a subordinate officer rank that is in charge of individual Escort-class vessels, with a Captain or Commodore holding overall command of an Escort squadron. However, an officer with the rank of Commander might also be found as the commanding officer of a squadron of system vessels, wing commander of the Attack Craft onboard a carrier ship, or placed in charge of an orbital station.Lieutenant - A lieutenant is a junior commissioned officer who is usually placed in direct command of system-defence ships and monitors. It is more common to find Lieutenants acting as second-in-command aboard Escort-class ships, as part of the vast bridge crew found on a capital vessel, or in an Attack Craft squadron acting as a Flight Leader. A Lieutenant is regarded as having true potential and the opportunity for further advancement up the Imperial Navy's chain of command.Midshipman - A Midshipman is the junior-most "officer" rank in the Imperial Navy. Midshipmen are actually better described as students with an officer's rank. Technically afforded an officer's respect, they are nevertheless still in demanding training to become true officers, and many of their duties are "hands-on" opportunities to learn. Midshipmen are so-called because they traditionally have quarters somewhere in a warship's midsection, far from the command bridge.