The Worst Witch
The Worst Witch is a series of children's books written and illustrated by Jill Murphy. The series are primarily boarding school and fantasy stories, with eight books already published. The first one, "The Worst Witch", was published in 1974 by Allison & Busby, and the most recent one, "First Prize for the Worst Witch", was published in 2018 by Puffin Books, the current publisher of all the series. The books have become some of the most successful titles on the Young Puffin paperback list and have sold more than 4 million copies.
Witch World
Witch World is a speculative fiction project of American writer Andre Norton, inaugurated by her 1963 novel "Witch World" and continuing more than four decades. Beginning in the mid-1980s, when she was about 75 years old, Norton recruited other writers to the project, and some books were published only after her death in 2005. The Witch World setting is one planet in a parallel universe where magic long ago superseded science; early in the fictional history it is performed exclusively by women. The series began as a hybrid of science fiction and sword and sorcery but for the most part it combines the latter with high fantasy. 
Witch World begins with what is now called the Estcarp cycle. These describe the adventures of Simon Tregarth from Earth, his witch wife Jaelithe, and their three children Kyllan, Kemoc and Kaththea.