J.K. Rowling began writing Harry Potter in 1990.
The idea came to her during a delayed train journey from Manchester to London in 1990. She said that the concept of a boy attending a school for wizardry arrived suddenly, and she spent the journey imagining the characters and setting. She began developing the story after returning home, although the first book would not be published for several years.
The date is sometimes confused with 1997, the year Harry Potter and the Philosopher’s Stone was published in Britain, or with 1995, when Rowling completed the manuscript. The series therefore had a long development period: conception in 1990, completion of the first manuscript in 1995, and publication in 1997.