Sir Fazle Hasan Abed, founder of Brac

When it comes to improving the lives of the world's poorest people, what really works? Sir Fazle Abed has spent much of his life trying to answer that question.

In the process he has created arguably the world's biggest development organisation, known by its initials Brac.

From its home in Bangladesh, to Afghanistan, to Africa, Brac has tied development to social change and economic self-help.

The ambition is huge but do the achievements match it?