I Know This to Be True About – Nelson Mandela: Guiding Principles by Sello Hatang and Verne Harris, copyright © 2020 the Nelson Mandela Foundation, in association with Blackwell & Ruth. Photographs by Andrew Zuckerman, copyright © Nelson R. Mandela. I Know This to Be True – Nelson Mandela: Guiding Principles will be published on 24 March 2020.