Writer Wangari Maathai, the first African woman to win the Nobel Peace Prize, has passed away. She was 71-years-old.

According to the AFP, Maathai (pictured, via) founded the Green Belt Movement, an environmental-activist group, in 1977. Her work provided the inspiration for several books including The Green Belt Movement: sharing the approach and the experience (1985), The Canopy of Hope: My Life Campaigning for Africa, Women, and the Environment (2002) and Unbowed: A Memoir (2006).

In an interview with Time , she explained how her work helps to promote peace: “We are sharing our resources in a very inequitable way. We have parts of the world that are very deprived and parts of the world that are very rich. And that is partly the reason why we have conflict.”