The founder of a project to improve access to education in South America has won a prestigious international education award.
Vicky Colbert has won this year's WISE Prize for her work with underprivileged families in Colombia.
She has been developing schools for poor rural children since the 1970s.
The annual award, announced at an education summit in the Gulf state of Qatar, has been likened to a Nobel prize for education.
Ms Colbert has been recognised for her work as co-founder of an education movement called Escuela Nueva, which was designed to improve the quality of education available in rural Colombia.
It was so successful that it was adopted in the 1980s as government policy - and it has been previously commended as a model for rural education by the World Bank and Unesco.
Ms Colbert became the country's vice-minister for education and has been a Unicef regional adviser.
And the project continued through decades of political upheaval and conflict.
The WISE Prize is worth $500,000 (£311,000) was launched in 2011 to recognise individual and collective achievement in education - in the way that Nobel prizes recognise contributions to science and literature.
The winner's name was revealed at the WISE summit taking place this week in Qatar which is part of that country's substantial investment in international education.
Although the wealthy oil-rich country has been associated with big spending, the prizes have rewarded authentic grassroots education projects.
The 2011 prize was awarded to Sir Fazle Hasan Abed, founder of the BRAC school project which began providing education for poor families in Bangladesh in the 1970s, and now teaches more than 120 million people in many of the world's most deprived communities.
Last year's winner was Madhav Chavan, creator of the Pratham charity, which has brought low-cost learning to poor communities across India.
The winner of the prize is decided by an international jury, chaired by Sheikh Abdulla bin Ali Al-Thani.
"Vicky Colbert has dedicated her life to revitalising education," said Dr Al-Thani.
"Her work has had a significant impact in Latin America and beyond, greatly expanding access to affordable quality education for the less-privileged."
Ms Colbert said the prize recognised the importance of learning for "human development" and it showed what "can be achieved when teachers and children are given the right tools to lead change".