Wangari Maathai receiving her Nobel Prize from Ole Danbolt Mjøs, Chairman of the Norwegian Nobel Committee, 10 December 2004.

Copyright © Pressens Bild AB 2004, SE-112 88 Stockholm, Sweden, telephone: +46-8-738 38 00 Photo: John McConnico

Wangari Maathai with her Nobel Medal and Diploma at the Nobel Peace Prize Award Ceremony, Oslo City Hall, Norway. The Kenyan ecologist is the first African woman awarded the Nobel Peace Prize.

© Pressens Bild AB 2004, S-112 88 Stockholm, Sweden, telephone: +46(0)87383800. Photo: John McConnico

Wangari Maathai delivers her Nobel Lecture after receiving the 2004 Nobel Peace Prize in the Oslo City Hall, Norway.

© Pressens Bild AB 2004, SE-112 88 Stockholm, Sweden, telephone: +46-8-738 38 00. Photo: John McConnico

At the Nobel Peace Prize Award Ceremony, Oslo City Hall, Norway, Kenyan dancers perform to celebrate ecologist Wangari Maathai's Nobel Peace Prize.

Copyright © Pressens Bild AB 2004, SE-112 88 Stockholm, Sweden, telephone: +46-8-738 38 00 Photo: Eric Feferberg

The award ceremony at Oslo City Hall, 10 December 2004.

© Knudsens fotosenter/Dextra Photo, Norsk Teknisk Museum.

Nobel Peace Prize Laureate Wangari Maathai, right, shakes hands with Norway's Queen Sonja in the Oslo City Hall, Norway. King Harald V is in the middle.

© Pressens Bild AB 2004, S-112 88 Stockholm, Sweden, telephone: +46(0)87383800. Photo: Bjorn Sigurdson

Kenyan ecologist and Nobel Peace Prize Laureate Wangari Maathai waves to 3,000 children invited by the organization Save the Children. To the right, Norway's Crown Prince Haakon.

© Pressens Bild AB 2004, S-112 88 Stockholm, Sweden, telephone: +46(0)87383800. Photo: Eric Feferberg

Nobel Peace Prize Laureate Wangari Maathai before entering Oslo City Hall, Norway, to receive the Nobel Peace Prize.

Copyright © Pressens Bild AB 2004, SE-112 88 Stockholm, Sweden, telephone: +46-8-738 38 00 Photo: John McConnico

Wangari Maathai viewing the traditional torch light procession in Oslo from a balcony at the Grand Hotel in Oslo, Norway, 10 December 2004.

© Knudsens fotosenter/Dextra Photo, Norsk Teknisk Museum.

Wangari Maathai in front of a painting of Alfred Nobel in the Nobel suite of Grand Hotel, Oslo, Norway, December 2004.

© Knudsens fotosenter/Dextra Photo, Norsk Teknisk Museum.

Wangari Maathai watching photos of previos peace laureates in the Committee room at the Norwegian Nobel Institute in Oslo, Norway, December 2004.

© Knudsens fotosenter/Dextra Photo, Norsk Teknisk Museum.

Wangari Maathai pays the traditional visit to the Nobel Foundation days after the award ceremony in December 2004. Copyright © Nobel Media AB 2004
Photo: Jonas Rosén

2004 Nobel Peace Prize Laureate Wangari Maathai during the interview at the Nobel Foundation in Stockholm, 2 April 2009. The interviewer is Marika Griehsel, freelance journalist. Copyright © Nobel Media AB 2009
Photo: Annalisa B. Andersson

2004 Nobel Peace Prize Laureate Wangari Maathai during the interview for Nobelprize.org in Stockholm, 2 April 2009. Copyright © Nobel Media AB 2009
Photo: Annalisa B. Andersson

2004 Nobel Peace Prize Laureate Wangari Maathai arrives in Stockholm, 2 April 2009. Copyright © Nobel Media AB 2009
Photo: Annalisa B. Andersson

Nobel Laureate Wangari Maathai is greeted by staff at the Nobel Peace Center during her visit in September 2006. Copyright © Nobel Peace Center 2006
Photo: Kirsti Svenning

Wangari Maathai in front of the wall exhibiting her Nobel Peace Prize awarded work during her visit to the Nobel Peace Center in September 2006. Copyright © Nobel Peace Center 2006
Photo: Kirsti Svenning

Wangari Maathai on one of her visits to the Nobel Peace Center – her "home away from home", as she put it.

Copyright © Nobel Peace Center 2005 Photo: Simen Myrberget

Wangari Maathai delivers her speech at the opening of the Nobel Peace Center, 11 June 2005.

Copyright © Nobel Peace Center 2005 Photo: Telenor

Portrait of Wangari Maathai, taken in 1989 during her time as the leader of the Green Belt Movement in Nairobi, Kenya.

Copyright © David Blumenkrantz Kindly provided by David Blumenkrantz