To celebrate the launch of TIME’s new multimedia project – 100 Photographs: The Most Influential Images of All Time – we asked leaders in a number of fields, from technology to the arts to business, to share the single photograph that most influenced their lives. Purchase the 100 Photographs book now.

Nelson Mandela has been one of the most inspirational figures throughout my life — both personally and in my career. I’ve drawn strength from his courage, perseverance and generosity like so many others. What I’m drawn to in this photo is his humble expression as he opens his arms to the people. I am so grateful to live in a world that has benefited from his life’s work.

Serena Williams is the No. 1 ranked female tennis player in the world.