Harbingers

The original meaning of harbinger is that of "one sent ahead to arrange lodgings" for a monarch, an army, etc., later (16th century) changing meaning to "forerunner". (cf. oldsaxon heriberga "army shelter" from heri "army" + berga "shelter"). An example of a harbinger is that of Constantine the Great, who, as legend goes, saw a vision in which either (depending on the version) a cross, a fish or a labarum monogram was emblazoned in the sky. A loud, steady voice then allegedly told him, In hoc signo vinces ("In this sign you will win"). He used that sign as standard in battle, and win he did, bringing Christianity to the Empire.