Albert Barnes Commentary Jeremiah 34:1

"The word which came unto Jeremiah from Jehovah, when Nebuchadnezzar king of Babylon, and all his army, and all the kingdoms of the earth that were under his dominion, and all the peoples, were fighting against Jerusalem, and against all the cities thereof, saying:" — Jeremiah 34:1 (ASV)

People - Peoples, that is, tribes, races, under the rule of one man.