Nicolas Flamel was a real person. I read about him in my early twenties when I came across one of the versions of his life story. It told how he had bought a mysterious book called The Book of Abraham the Jew, which was full of strange symbols and which Flamel realised were instructions on alchemy. The story went that he subsequently made it his life’s work to produce the Philosopher’s Stone.
The real Flamel was a wealthy businessman and a noted philanthropist. There are streets in Paris named after him and his wife, Perenelle.
I remember having a highly detailed and exceptionally vivid dream about Flamel, several months into the writing of Philosopher’s Stone, which was like a Renaissance painting come to life. Flamel was leading me around his cluttered laboratory, which was bathed in golden light, and showing me exactly how to make the Stone (I wish I could remember how to do it).