Forbes' Power Women list isn't about celebrity or popularity; it's about influence. Queen Rania of Jordan (No. 75), for instance, is perhaps the most listened-to woman in the Middle East; her Twitter feed has 600,000 followers. 

In assembling the list, Forbes looked for women who run countries, big companies or influential nonprofits. Their rankings are a combination of two scores: visibility--by press mentions--and the size of the organization or country these women lead. 

At No. 1, for the fourth consecutive year, is German Chancellor Angela Merkel. Up for reelection this September, she is leader of the world's fourth-largest economy. She faces a tough year: Germany's GDP is expected to shrink this year despite a small uptick in the second quarter.