The young and the powerful of 2012

Twelve people under 50 find a spot in the list of most powerful people released by Forbes. Leading the pack is Facebook co-founder Mark Zuckerberg. Google's Sergey Brin and Larry Page are ranked third. Here's the list:

Mark Zuckerberg, 28
Zuckerberg is the co-founder, chairman and chief executive of social networking site Facebook. The company began trading on the Nasdaq in May this year.

Kim Jong-Un, 29
Kim Jong-Un is the supreme leader of North Korea, and the son of Kim Jong-il. He was officially declared the supreme leader following the state funeral for his father on December 28, 2011.

Larry Page and Sergey Brin, 39
They are the founders of search engine giant Google, a company they set up while attending Stanford University. Page (left) is now the chief executive of the company, while Brin handles special projects.

Elon Musk, 41
Musk is a South African-American entrepreneur and inventor best known for founding SpaceX, and co-founding Tesla Motors and PayPal. Cash-strapped NASA has retired its Space Shuttle fleet and will use SpaceX vehicles to haul cargo to and from the International Space Station.

Robin Li, 44
Robin Li is the co-founder and chief executive of search engine Baidu. He is among the richest men in China with an estimated net worth of $7-10 billion.

Reid Hoffman, 45
Hoffman is an American entrepreneur, venture capitalist and author. He is best known as the co-founder of LinkedIn. The world's most powerful venture capitalist and the most-connected man in Silicon Valley can make or break a start-up, writes Forbes.

David Cameron, 46
Cameron is the Prime Minister of the United Kingdom. Two years into office, he has gone from being called the second coming of Margaret Thatcher to standing in the shadow of Europe's new Iron Lady, Angela Merkel, writes Forbes.

Enrique Pena Nieto, 46
Enrique Pena Nieto is the President of Mexico. He assumed office on December 1, 2012.

Dmitry Medvedev, 47
Dmitry Medvedev is the Prime Minister of Russia since May 2012. He previously served as the third president of the country, from 2008 to 2012. At the age of 43, he was the youngest Russian president.

Jeff Bezos, 48
Bezos is the founder and CEO of online company Amazon.com, the largest retailer on the Internet. He was also the Time Person of the Year in 1999.

Rostam Ghasemi, 48
Rostam Ghasemi is the former commander of Iran's Revolutionary Guard Corps and serves as the country's oil minister and as president of OPEC.