Kumi Naidoo
Kumi Naidoo was just 15 years old when he became an activist, leading a student demonstration against apartheid in education in his native South Africa.
His mother's suicide encouraged him to give his life to eliminating apartheid in South Africa.
Risking his life many times, he was eventually forced to flee the country he loved, so he came to the UK to become a Rhodes Scholar.
When Nelson Mandela was freed from prison, Kumi went back to South Africa to work for the ANC and help Nelson Mandela to become South Africa's first democratically elected president.
Since then he has worked for many other causes including going on a 21 day hunger strike to raise awareness of the plight of starving people in Zimbabwe.
And now he's the first South African and the first outsider to be elected as Director of Greenpeace International.
Kumi Naidoo spoke to Matthew Bannister and told him all about his remarkable life.