An angelic order, the best known members of which were Gabriel, Michael and Raphael. It was Raphael who, in Milton's Paradise Lost, was sent by God to put man on guard against Satan. This forewarning rendered all excuse for disobedience null. Michael was the archangel who fought against Satan and those angels who sided with him during his three-day rebellion in heaven. Gabriel (the name means Man of God) was charged with protecting Adam and Eve and he expelled Satan from the garden of Eden; he was also the angel of the Annunciation.
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.