Africa's first elected female head of state, a Liberian peace activist, and a human rights activist from Yemen are the three female winners of this year's Nobel Peace Prize. When they received the award Saturday in Oslo, Norway, they joined a special group.
A total of 15 women have received the Nobel Peace Prize since it was first awarded in 1901.
The first was Austrian writer and peace activist Bertha von Suttner in 1905.
This year, the Norwegian Nobel Committee split the $1.5 million prize among three women.
President Sirleaf became Liberia's first elected female president in 2006. Fellow Liberian Leymah Gbowee is an activist recognized for uniting women against the country's warlords. And Tawakkol Karman is a Yemeni journalist and the first Arab woman to receive the prize.
In Oslo for the award ceremony, President Sirleaf called the prize a "wonderful recognition" of the inequalities women have suffered.
"I feel honored to represent them, their own aspirations and expectations for a better world, to be able to recognize the inequities that they have faced in the lack of access to those basic things that allow the comfort of life," said Sirleaf.
The 2011 recipients join an elite group of women winners.
Among them is the late Mother Teresa, a Roman Catholic nun who won in 1979 for her humanitarian work.
1991's recipient was Burmese pro-democracy leader Aung San Suu Kyi. Iranian human rights lawyer Shirin Ebadi won in 2003.
The most recent woman to receive the prize was Kenyan environmentalist Wangari Maathai in 2004. Maathai died in September after a long battle with cancer.
Norwegian Nobel panel chairman Thorbjoern Jagland says women are critical to peace.
"We cannot achieve democracy and lasting peace in the world unless women obtain the same opportunities as men to influence developments at all levels of society," said Jagland.
Women have also won Nobel Prizes in the sciences and literature, with one woman, radiation researcher Marie Curie, honored twice, first in physics and years later in chemistry.
Female Nobel Peace Prize Winners 1905-2011: