In the O.T. this word is used for one filling any office of rule or command: as the head of a tribe, Numbers 2:3-29; commander of an army, etc. The person who appeared to Joshua as 'a man' declared himself to be 'captain of the Lord's host.' He told Joshua to remove his shoes from his feet, for the ground was holy, evincing that he was God's representative to lead their warfare. Joshua 5:14,15 . In the N.T. the Lord is called 'Captain' of our salvation, ἀρχηγός, 'chief leader.' Hebrews 2:10 .
There was also a 'CAPTAIN OF THE TEMPLE,' στρατηγός. Luke 22:4,52; Acts 4:1; Acts 5:24,26 . This word is literally 'the leader of an army;' it is also applied to magistrates, Acts 16:20 , but the captain of the temple was set not over the soldiers, but over the priests and Levites: cf. Numbers 3:32; 1 Chronicles 9:11; Jeremiah 20:1 .
THE CHIEF CAPTAIN or HIGH CAPTAIN is χιλίαρχος, lit. 'Captain of a thousand,' applied to the chief of the soldiers in Jerusalem. Acts 21 - 25.
CAPTAIN OF THE GUARD, Acts 28:16 , is στρατοπεδάρχης,properly 'commander of a camp,' but here the prefect of the Praetorian Guard, an officer to whom state prisoners were entrusted at Rome.