Apparently the evil princess in Princess Gwenevere and the Jewel Riders did have a medieval legendary counterpart!
Kyra Kale tou Oreon, Lady Kale of the Mountains (pronounced Ka-le) was notoriously a mistress of magic and evil spirits. She lived off in the wilds away from human beings and was always up for causing fairy tale and folk tale trouble, back in the Middle Ages and even in stories today. Her legend may be descended from stories about Artemis.
Kale always bothered me in the original series, as it seemed like she was meant to stand for _something_ I wasn’t getting. So this pleases me.