Carlotta

 was a friend of Endora's during the Middle Ages, and they arranged a marriage between their children, Juke and Samantha. However, Samantha is already married to Darrin, and was never told about the arranged marriage.

Carlotta traps Darrin with magic so Samantha and Juke could marry, but Samantha teaches Juke to stand up to his mother, which allows Darrin to be set free, and Juke to marry whomever he wants.