An Etymological Dictionary of the German Language/Annotated/Standarte
Standarte, feminine, ‘standard, banner,’ from the equivalent Middle High German stanthart (standert), masculine. Borrowed in the 13th century from Old French estendard (French étendard), ‘flag,’ or preferably from the equivalent Italian stendardo, which. is based on Latin extendere. From the same source English standard is derived.