Commodore

The term Commodore typically denoted senior Navy officers commanding groups of ships rather than individual vessels, but it was used in a number of different ways by various military hierarchies.
Most typically, the title "Commodore" was associated with a distinct rank between Captain and Rear Admiral; officers of this rank might serve as senior captains of important ships, or else could command flotillas, squadrons or taskforces, usually under superior flag officers. 
This usage of the term was established in the New Republic and Galactic Alliance rank hierarchies, perhaps based on earlier practice under the Old Republic: for example, during the Swarm War (35-37 ABY), Gavin Darklighter commanded a taskforce in the Fifth Fleet with the rank of Commodore. However, the New Republic also accorded a seperate title of "Commodore" to some very high-ranking officers, such as General Han Solo, who was so styled when he was appointed as commander of the entire Fifth Fleet in 17 ABY.
Under the Galactic Empire, in contrast, the rank between Line Captain and Rear Admiral had been Commander, and the term "Commodore" was used instead as an alternate title for a Systems Admiral, a mid-ranking command officer within the Navy hierarchy of a Sector Group.
Other military forces used the term "Commodore" in different ways; for instance, the Utapau Skyforce had a rank of Air Commodore.
==Behind the Scenes==
The title of Commodore has a complex real-world history, beginning during the Anglo-Dutch wars of the seventeenth century, when the title of "Commander" was accorded by both sides to a senior captain commanding a detached squadron where no Admiral was present. Gradually, the position of "Commodore" gained in formality within the British Royal Navy, and by the nineteenth century, there were two classes of Commodore, each with their own uniforms, pennants and perquisites; but Commodores reverted to Post Captain when they hauled down their broad pennant, and the title did not become a permanent rank until 1996. The comparable Dutch grade of Commandeur had similarly remained temporary until 1955, although the parallel Kapitan-Commandor was a permanent rank in Imperial Russia from the early 1700s until 1827.
A seperate development from the seventeenth-century usage was that the title of "Commodore" came to denote the senior ship's captain of a British merchant marine convoy; more recently, this usage has become general to the senior captains of yacht clubs and shipping lines throughout the English-speaking world. In a seperate development, when the Royal Flying Corps became the Royal Air Force in 1918, a permanent rank of Air Commodore was introduced, inspired by the naval rank, and equivalent to an Army Brigadier or a Navy Commodore; unlike a naval Commodore, the RAF Air Commodore was always a permanent rank, and it was subsequently adopted in some other Commonwealth countries.
Over the centuries, ranks derived from the "Commander" and "Commodore" of the 1600s have been adopted in numerous other countries, and while many navies have directly immitated English practice, others have diverged markedly from it: in the Polish Navy, grades of Kommandor now cover the ranks between Captain and Lieutenant Commander, while a Kapitan marynarki is equivalent to Lieutenant. In the Imperial German Navy during the First World War, a title of Kommodore was borne by any officer leading a flotilla of vessels, particularly in the U-boat command.
A special, and complex, case is the United States Navy, which borrowed the temporary position of Commodore from British usage in the eighteenth century: in the early decades of the Republic, this was the most prestigious position in the service, as there were no Admirals, and accordingly, ex-Commodores who had reverted to Captain retained the title as a courtesy rank. In 1859, the grade was renamed as "Flag Officer", but in 1862, substantive ranks of Commodore and Rear Admiral were created. In 1899, however, Commodore became Rear Admiral (lower half), and since then, the rank of Commodore has only been briefly revived, between 1942 and 1950, and 1982 and 1985. Since the 1980s, "Commodore" has also been used semi-formally as a title for senior Captains commanding squadron-strength forces of ships, or wings of aircraft, and it is this usage that is now current.