blue mantle

Century Dictionary and Cyclopedia

1. n. The title of one of the English pursuivants-at-arms. The office was instituted either by Edward III. or by Henry V., and named in allusion to the robes of the order of the Garter, or, as some suppose, to the color of the arms of France.

GNU Webster's 1913

1. adj. (Her.) one of the four pursuivants of the English college of arms; -- so called from the color of his official robes.