Maria Ramos

Barclays Africa is a very different bank than it was when Ramos took the reins there in 2009. In her eight years at the firm, the Portuguese-South African economist has skillfully led the company's transformation, completed earlier this year, from Barclays subsidiary to standalone entity with 11.8 million customers and a presence in 12 countries. Though recession in South Africa has tested the bank locally, it added 2.5 million customers and now counts on foreign markets for nearly a quarter of its revenue. Ramos, the only woman to helm one of the 40 largest companies on the Johannesburg Stock Exchange, earlier this summer joined the prestigious Group of 30,a select body of economists that includes Ben Bernanke and Bank of England Governor Mark Carney,where she is also the only woman.