The position of Captain of the Line or Line Captain was a military rank in the Imperial Navy. A Line Captain typically commanded a tactical unit known as a line of battle, comprising between five and twenty corvettes, frigates or cruisers. Officers of the same rank could often command a single Star Destroyer, or serve as the adjutant to an Admiral.
In terms of the Navy's rank hierarchy, the responsibilities of Line Captains were similar to those of Commanders such as Pter Thanas, Kratas, and Ait Convarion; but it seems likely that the two ranks were distinct, inasmuch as Commanders were senior to all officers holding a rank of Captain. The rank of Line Captain was thus probably broadlly analogous to that of Captain in many other space fleets, although there may have also been subordinate grades of Captain in the Imperial rank structure.