J.K. Rowling reached $1 billion in 2011; a year later, after donating an estimated $160 million, she fell off the Forbes billionaires list

J.K. Rowling built an empire after launching the Harry Potter series, earning her the distinction of being the first billionaire author, according to the Guinness Book of World Records.

In the late 1990s and early 2000s, the fantasy book series and its film adaptations became a massive hit after the British writer published the first book in 1997, while the film Harry Potter and the Sorcerer's Stone premiered in November 2001.

It was an instant box office hit, sparking a global phenomenon among avid readers, also known as Potterheads.