Eventually the potato's undeniable advantages over grain would convert all of northern Europe, but outside of Ireland the process was never anything less than a struggle. ... Louis (XVI) hatched an ingenious promotional scheme. He ordered a field of potatoes planted on the royal grounds and then posted his most elite guard to protect the crop during the day. He sent the guards home at midnight, and in due course the local peasants, suddenly convinced of the crop's value, made off in the night with the royal tubers.