Dux (, pl.: ducēs) is Latin for "leader" (from the noun dux, ducis, "leader, general") and later for duke and its variant forms (doge, duce, etc.). During the Roman Republic and for the first centuries of the Roman Empire, dux could refer to anyone who commanded troops, both Roman generals and foreign leaders, but was not a formal military rank. Roman Empire. Original usage. Until the 3rd century, dux was not a formal expression of rank within the Roman military or administrative hierarchy. In the Roman army, a dux would be a general in charge of two or more legions.
https://en.wikipedia.org/wiki/Dux
Dux (, pl.: ducēs) is Latin for "leader" (from the noun dux, ducis, "leader, general") and later for duke and its variant forms (doge, duce, etc.). During the Roman Republic and for the first centuries of the Roman Empire, dux could refer to anyone who commanded troops, both Roman generals and foreign leaders, but was not a formal military rank. Roman Empire. Original usage. Until the 3rd century, dux was not a formal expression of rank within the Roman military or administrative hierarchy. In the Roman army, a dux would be a general in charge of two or more legions.
