The rise of Tim Cook, the most powerful CEO in the world

In August 2011, Tim Cook took the job as CEO of Apple, leaving many wondering if he could fill the shoes left by his friend and mentor, Steve Jobs.

Today, Apple is the most valuable company in the world, and products like the iPhone continue to rule the market, leaving Cook looking pretty good.

But when he was first announced for the role, he was a big question mark. He had come out of seemingly nowhere to lead such a big, important company.Here's how Tim Cook rose through the ranks and became Apple's CEO.