First lieutenant
First lieutenant was a military rank. A traditional infantry rank, first lieutenant was the second lowest officer grade, senior to a second lieutenant. Infantry lieutenants fall below captains, and command a platoon, consisting of about thirty troops. In comparison to naval ranking systems, a first lieutenant was equivalent to lieutenant junior grade. Prior to the late 19th century, in the British navy, first lieutenant referred to a position, a ship's most senior lieutenant serving as second in command, rather than to a rank.

First lieutenants existed in other Earth nations, such as World War II Germany. In the German armies, this was translated as Oberleutnant, but in the SS, first lieutenants were referred to as Obersturmführer ("senior storm leader"). The collar insignia for this was a black square bordered with white, with three silver pips in a diagonal line above a doubled silver stripe (a single pip was also worn on each epaulet). 

In an alternate timeline in which Na'kuhl time-travelers had allied themselves with Adolf Hitler's Nazis in 1944, an Obersturmführer first lieutenant named Ghrath was executive officer to Vosk. ()

This rank was used by the United States military and police, represented by a single rectangular silver bar uniform insignia. 

A US Marine Marine lieutenant assigned to the aircraft carrier  was one of the troops involved in the hunt for intruding time traveler Pavel Chekov in 1986. ()

In the Hirogen holodeck recreation of World War II, Tom Paris portrayed a US Army first lieutenant named Bobby Davis. ()

Appendices

Background information 
The Marine 1st lt. was played by Donald W. Zautcke, an actual USMC officer.

According to the , 1st lieutenant was a rank in the Military Assault Command Operations in the 2150s. The insignia for this rank was on display in a diagram of MACO ranks and insignia.

External link 
 

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Military ranks