The BBC history page has an article detailing the life and troubles of Helen Duncan, the second-to-last woman to be tried for witchcraft in the U.K.
That's right, she's the penultimate convicted witch in Great Britain. A woman named Jane Rebecca Yorke gets the honor of being the last witch on the books. Her story is equally interesting, but being elderly, Yorke didn't serve any jail time. Helen Duncan did.
[Tip of the pointy hat to Jen Newby's Writing Women's History blog.]