The Worst Witch
Mildred "Millie" Hubble is the protagonist of the series. She is a good-hearted, but bungling young witch-in-training, who never seems to get anything right. She is friends with Maud Spellbody and Enid Nightshade and has a strong rivalry with Ethel Hallow. It is Miss Hardbroom, her potions teacher, who calls her "The Worst Witch".
The Worst Witch
"The Worst Witch All at Sea" () was published in 1993. It is the only book in the series not set in Miss Cackle's Academy for Witches, but by the sea instead.