One Star Admiral

One star admiral (or rear admiral lower half) is a rank of flag officer in naval services and space forces, such as Starfleet. 

Specifics
One star admiral is the most basic flag officer rank, a grade higher than a captain and a grade below rear admiral and other admiral grades in most rank structures, although some organizations will use the approximately equivalent rank of commodore, which is also used as a title for lower ranking commanders who are nominally in charge of others of the same rank. The one star rank is roughly equivalent with the authority of a brigadier of military forces. The Romulan Star Empire has two ranks, senior centurion (enarrain in the Romulan language) and commander general (khre'riov), that are analogous to a one star admiral's standing. In the Cardassian language, jagul is a Cardassian flag officer rank title which, in translation to Federation Standard, is approximately equivalent to a one star admiral.

In military parlance, it is acceptable and normal to refer to a one star admiral simply as "admiral" in most forms of address.

Starfleet one star admirals
In the Starfleet uniform insignia used in the mid-23rd century, a one star admiral wore the same service uniform rank insignia as a commodore, a thick sleeve stripe of gold with two gold braids on the edges. Admirals Kirk and Balzay wore this insignia in the year 2270. 


 * It is likely that in other uniform designs a rear admiral lower half would also wear an insignia similar or identical to a commodore's, just as the 2260s uniforms were shown to do.

In the uniform insignia introduced in the mid-24th century, a one star admiral wore a triangular rank braid (with no additional pips) as their service rank insignia. 


 * The correlation between this lowest admiral rank and the uniform insignia that first appeared in "Too Short a Season" is because other admirals in "Conspiracy" were shown wearing higher rank insignia, and the single braid insignia was the most basic one shown.

Another 2350s jacket insignia had a rectangular gold border around a single pip. 


 * The appearance of Edward Janeway's vice admiral insignia in "Coda" gives us the inference that the rectangular border insignia was used as early as the 2350s, although this information could be illusory in nature—Janeway's appearance was shown from the point-of-view of Kathryn Janeway's hallucination, and showed a uniform that could have been interpreted as being a few years too modern for the 2350s.

A style of uniform worn around 2365 had admiral insignia placed vertically on a division color collar. This style of uniform fell out of use, but was known to be used concurrently with other types introduced with the uniform changes of the next few years. 


 * The admiral uniform introduced in "The Measure of a Man" had only two canon appearances, but was used into 2366 in a series of comics stories, that took place after canon episodes introduced the newer style in TNG season 3.

In a redesign of the admiral's service uniforms of 2365 and 2366, the insignia of one gold pip enclosed in a square or rectangular gold border was used as the insignia for one star admirals, showing the origin of the "one star" name. This insignia continued into later uniform designs of the 2370s. 


 * The Star Trek Encyclopedia shows the insignia in a square-shaped pin, while the New Frontier comic appearances depicts a rectangular pin. It is possible the insignia changed over the years between the 2360s and the 2370s when those references took place, respectively.

Federation Starfleet

 * Mark Jameson (prior to 2364)
 * Edward Jellico (2370)
 * Balzay (c. 2270)
 * James T. Kirk (2270)
 * Gregory Quinn (prior to 2364)
 * Elizabeth Shelby (2379)