Captain Mid was a military rank employed within the Chiss Ascendancy's Chiss Expansionary Defense Fleet. It was a rank positioned under the rank of senior captain and held a higher position than junior captain. Ufsa'mak'ro, a Chiss member of the Expansionary Defense Fleet, held the rank of mid captain circa 19 BBY, and served on the Chiss heavy cruiser named Springhawk.
The rank of mid captain was initially featured in the 2020 book Thrawn Ascendancy: Chaos Rising, which initiated Timothy Zahn's Star Wars: The Ascendancy Trilogy.