Dr. Jane Goodall, founder of the Jane Goodall Institute and a United Nations Messenger of Peace, died in her sleep on Wednesday, Oct. 1. at the age of 91.

“She was a remarkable example of courage and conviction, working tirelessly throughout her life to raise awareness about threats to wildlife, promote conservation, and inspire a more harmonious, sustainable relationship between people, animals and the natural world,” the Jane Goodall Institute stated on its website.

In July 1960, at the age of 26, Goodall journeyed from England to what is now Tanzania to venture into the little-known world of wild chimpanzees. Equipped with a notebook, binoculars and an innate fascination for wildlife, Goodall broke barriers to change the way humans saw their closest relatives and themselves.

While her choice to give the chimpanzees names instead of numbers raised eyebrows, she ultimately made groundbreaking discoveries on the use of tools and the levels of social and emotional intelligence in primates. A true environmental celebrity of her time, Goodall spent her life studying animals and educating the world about our connection the natural environment.

Until her death, Goodall continued to meet with students and global leaders to speak about her remarkable life and enduring vision for a more just, empathetic and sustainable world. She died while on a speaking tour. When not traveling, she lived in her childhood home in Bournemouth on the south coast of England.

“People say think globally, act locally,” Goodall said. “Well, if you think globally, it is overwhelming and you do not have enough energy left to act locally. Just act locally and see what a difference you can make … So when you hear ‘think globally, act locally,’ turn it around: Act locally, then you dare think globally.”