Commander/Legends

Commander is a military rank or title, and was used in several different ways during the era of the Clone Wars, Galactic Civil War and Yuuzhan Vong invasion.

Military Usage
As a generic mode of address, "commander" was appropriate to many military officers - almost anyone holding a distinct unit or ship command could be called "commander" in this way, although the commanding officers of capital ships usually preferred to be addressed as "Captain". Alongside this generic usage, "Commander" was also used as a specific rank, with several different meanings depending on the context.

Navy Ranks

 * In many naval hierarchies, including those of the Old Republic, the Rebel Alliance, the New Republic and the Galactic Alliance, a Commander ranked below a Captain.
 * In the Imperial Navy, however, the title of Commander usually indicated officers ranking above a Captain but below Admirals, equivalent to a New Republic Commodore.

Army/Starfighter Ranks

 * In Imperial Starfighter and Army units, a Commander apparently ranked between a Captain and a Major.
 * In Rebel Alliance and New Republic Starfighter Command organizations, references exist to a rank of Commander, sometimes specifically "Flight Commander" or "Wing Commander", covering at least one tier of the hierarchy between Captain and Colonel; by the time of the Galactic Alliance, these titles had apparently been replaced by Major and Lieutenant Colonel.
 * The promotion of Commander Eldo Davip to Major General after the Battle of Borleias suggests that in some elements of the New Republic or Galactic Alliance military, a rank of Commander may replace Brigadier.

Other Systems

 * In the GAR, the rank of Commander was borne by senior clone officers, and some Jedi, including many padawans.
 * Among the Yuuzhan Vong, most warship captains and a few taskforce commanders bore a rank of Commander, and superior officers were known as Supreme Commanders.
 * In the armed forces of the Chiss Ascendancy, variations on "Commander" were used as ranks or titles in a variety of different contexts. In the years before the Clone Wars, a frontier patrol group of the Expansionary Fleet could be commanded by an officer with the title of Force Commander, often simply styled "Commander" (Crahsystor in Cheunh). Much later, in c. 19-22 BBY, examples are also known of a "Phalanx Commander", "Station Commander" and "Cadet Commander", the last-named of these being an office cadet, also addressed as as "Lieutenant". By the time of the Swarm War in 37 ABY, the term "Commander" was used in Basic to translate the rank analogous to a naval Commander in the Galactic Alliance, one grade below Captain, but is not clear whether this usage corresponded to any of the earlier terminology.

Superior Ranks

 * The title "Commander-in-Chief" was used by some civilian heads of state in their capacity as head of their government's military forces - for instance, the Chief of State of the Alliance to Restore the Republic was also, ex officio, Allied Forces Commander-in-Chief.
 * The position of Supreme Commander was borne by very senior officers serving various regimes, including the Grand Admiral who was effectively the head of state of Imperial Space after 19 ABY.

Behind the Scenes
The usage of the rank of Commander in Star Wars often seems confusing, as it does not always correspond to the real-life Anglo-American model, in which Commander primarily refers to a naval rank immediately below Captain, as used in the Royal Navy, United States Navy, and borrowed in the form Wing Commander by the Royal Air Force. Abstract real-world models cannot, however, override the empirical evidence of the official sources, and the canon material shows frequent departures from the Anglo-American model. Nevertheless, a real-world parallel can be found for almost every usage represented:
 * With few exceptions, the Galactic Alliance makes use of American-style ranks, and, to a slightly lesser extent, this is also true of the New Republic.
 * The Imperial Navy rank of Commander is unambiguously treated as equivalent to a Commodore on more than one occasion. This corresponds to the Dutch Commandeur and the Russian Imperial rank of Kapitan-Kommandor.
 * The use of "commander" as a generic mode of address, and also the placing of the specific rank in the Imperial Starfighter and Army hierarchies, corresponds to the usage of French Commandant.
 * The Alliance's "Flight Commander" and "Wing Commander" are the most problematic, not least because the precise relationship of these two ranks is unclear. They may represent the single Imperial Starfighter Command rank of "Commander", or else two ranks fusing Imperial and Royal Air Force patterns, but a broad parallel might also be found in the replacement of the ranks of Major, Lieutenant-Colonel and Colonel with chef de batallion and chef de brigade in the French Revolutionary armies.