Tawakul Karman, a Yemeni journalist and activist, is one of three women awarded the 2011 Nobel Peace Prize. She becomes the first Arab woman to win the prize.
The 32-year-old mother of three founded Women Journalists Without Chains in 2005.
She has been a prominent activist and advocate of human rights and freedom of expression for the last five years, and led regular protests and sit-ins calling for the release of political prisoners.
The Norwegian Nobel Committee cited Ms Karman and the two other winners for their "non-violent struggle for the safety of women and for women's rights to full participation in peace-building work".
The Nobel jury specifically lauded Ms Karman for playing, "in the most trying circumstances, both before and during the Arab Spring... a leading part in the struggle for women's rights and for democracy and peace in Yemen."
Ms Karman told the BBC Arabic Service: "I'm so happy with the news of this prize and I dedicate it to all the martyrs and wounded of the Arab Spring… in Tunisia, Egypt, Yemen, Libya and Syria and to all the free people who are fighting for their rights and freedoms.
"Actually I didn't know I was nominated for the Nobel Peace Prize until now. I only knew about it through BBC Arabic and al-Jazeera, so thank you very much."
In comments to the AFP news agency she said that the prize was "a recognition by the international community of the Yemeni revolution and its inevitable victory".
Ms Karman has led rallies in the continuing protests against the rule of President Ali-Abdullah Saleh.