J.K. Rowling taught English in Portugal before returning to Britain to write Harry Potter. She moved to Porto in 1991 and worked as an English teacher while living there.
During her time in Portugal, Rowling married Portuguese television journalist Jorge Arantes. Their daughter, Jessica, was born in 1993. Rowling later left Portugal and returned to the United Kingdom with Jessica, settling in Edinburgh.
The Harry Potter manuscript was developed over several years. Rowling had first conceived the idea during a train journey from Manchester to London in 1990, before her move to Portugal. The Portuguese period therefore formed part of the book’s development but was not the moment when the concept was first invented.
Biographies sometimes mention France because Rowling studied French and spent a year in Paris as part of her university course. That is a different part of her life: Portugal was the country where she taught English.