What is "protostates"

A protostates (, "the one who stands first/in front"), in Ancient Greece, was the man in front of an epistates (the one who stands behind). The Greek phalanx was made up of alternate ranks of protostates and epistates. Thus, in a file of 8 men, the protostates were the men in positions 1,3,5 and 7, while the epistates occupied positions 2,4,6 and 8. The term remained in use into the Byzantine Empire. The foremost protostates of a file ( lochos) was called a lochagos .