The Witches series of books follow the exploits of a coven of witches who live in the Ramtops kingdom of Lancre. Primarily these books follow Granny Weatherwax (who appears in all of the books) and Nanny Ogg (who appears in all but the first); they are initially joined by Magrat, but she eventually leaves the coven to be replaced by Anges Nitt. Granny and Nanny also appear as supporting characters in the subsequent Tiffany Aching series.
The Witches series of books comprises six novels:
The short story "The Sea and Little Fishes" acts as a bridge between the Witches book and the Tiffany Aching series. Granny and Nanny go on to appear in the Tiffany Aching books: both have a cameo in The Wee Free Men; Granny appears in all the rest, while Nanny only in Wintersmith, I Shall Wear Midnight and The Shepherd's Crown. Nanny also has a significant cameo in Thief of Time, while Granny appears briefly in The Science of Discworld II: The Globe.