David Cameron

• Prime Minister, United Kingdom
• Age: 47
• Residence: London, United Kingdom
• Country of Citizenship: United Kingdom
• Education: Master of Science, Oxford University
• Marital Status: Married
• Children: 4

• Profile

  The Conservative PM guides the world's sixth largest economy. He has recently been criticized for a flip-flop approach to green taxes after he pledged to slash household energy bills.

Michael Duke

• CEO, Wal-Mart Stores
• Age: 64
• Residence: Rogers, AR
• Country of Citizenship: United States
• Marital Status: Married
• Children: 3

• Profile

  Chief of the world's No. 1 retailer (just under $470 billion in sales in 2012) and biggest private employer (2.2 million employees). Wal-Mart can make or break a company simply by deciding to stock its product.

Mario Draghi

• President, European Central Bank
• Age: 66
• Residence: Rome, Italy
• Country of Citizenship: Italy
• Education: Doctorate, Massachusetts Institute of Technology
• Marital Status: Married
• Children: 2

• Profile 

  As chief banker of the world's largest ­currency area--the euro zone's collective GDP is now nearly $17 trillion--Draghi faces the Herculean task of trying to maintain financial unity across 17 countries.

Abdullah bin Abdul Aziz Al Saud

• King, Saudi Arabia
• Age: 89
• Residence: Riyadh, Saudi Arabia
• Country of Citizenship: Saudi Arabia
• Marital Status: Married
• Children: 22

• Profile

   Saudi Arabia's aging monarch holds the keys to Islam's two holiest sites and the world's second largest crude oil deposit of some 265 billion barrels, amounting to about 18% of global reserves. The Kingdom boasts a $727 billion GDP, putting it in the top 20 richest countries worldwide.

Ben Bernanke

• Chairman, Federal Reserve, United States
• Age: 60
• Residence: Washington, DC
• Country of Citizenship: United States
• Education: Doctorate, Massachusetts Institute of Technology; Bachelor of Arts / Science, Harvard University
• Marital Status: Married
• Children: 2

• Profile

   Big Ben is stepping down when he term ends in January 2014, and Janet Yellen has been nominated to lead the Fed next year. Bernanke has steered the Fed during some of the biggest financial challenges since the Depression.