J.K. Rowling’s publishers requested the initials J.K. for her first Harry Potter book.
Rowling was born Joanne Rowling and did not originally have a middle name. Bloomsbury asked her to use two initials because it believed young male readers might be less likely to choose a book written by a woman. Rowling selected K to honor her paternal grandmother, Kathleen Ada Bulgen.
The author therefore became known publicly as J.K. Rowling, even though the second initial was adopted for publishing rather than inherited at birth. Her first Harry Potter novel appeared under that name in 1997, and the initials became one of the most recognizable author brands in modern publishing.
Rowling later used other author identities for different types of writing. She published The Casual Vacancy under the Rowling name and wrote the Cormoran Strike novels as Robert Galbraith. These names should not be confused with characters or fictional narrators in her books.