Spanx founder Sara Blakely is first female billionaire to donate half her fortune to charity

Entrepreneur Sara Blakely has become the first female billionaire to donate half her fortune to the Bill Gates and Warren Buffett Giving Pledge, specifically to "invest in women".

Sara Blakely, the youngest woman in the world to become a billionaire on her own, is donating half her fortune to the Bill Gates and Warren Buffett Giving Pledge. 

The youngest woman in the world to make $1bn (£650m) on her own was approached by Bill Gates to commit half her wealth to the philanthropy, according to forbes magazine.

The giving pledge,  run by Gates and Buffet, was launched in June 2010 and encourages the world's richest people to give away at least half of their fortune.

Sara Blakely said she decided to join the scheme to invest in women - "one of the greatest returns on investment".

She wrote: "I pledge to invest in women because I believe it offers one of the greatest returns on investment. I am committed to the belief that we would all be in a much better place if half the human race (women) were empowered to prosper, invent, be educated, start their own businesses, run for office – essentially be given the chance to soar."

Forbes named Ms Blakely the youngest self-made female billionaire in the world last year. Her company, Spanx, manufactures shaping underwear that promises to make women look as though they have dropped a dress size.

In a longer letter on the Giving Pledge site, Ms Blakely added: "Since I was a little girl I have always known I would help women. In my wildest dreams I never thought I would have started with their butts. As it turns out, that was a great place to start."
The letter in full:

Other rich people to have donated to the Giving Pledge include British politician Lord Ashcroft, Steve Bing, Joe Craft and Shelby White.