PHOTOS: The world's greatest leaders

What do Taylor Swift and Pope Francis have in common? They're part of Fortune Magazine's "World's Greatest Leaders" list.

Fortune released today their list of the "World's Greatest Leaders," a collection of innovators, politicians, protestors, and pop stars who continue to captivate and shape the world in which we live. Fortune says that they assembled a wide group of leaders, even some without formal titles.

"We set out to find singular leaders with vision who moved others to act as well, and who brought their followers with them on a shared quest. We looked for effectiveness and commitment and for the courage to pioneer. All had to be active in leadership roles, though a long history of leading is something that many on our list share," Fortune said in their list.

Coming in at the top spot was Apple CEO Tim Cook, who took over reigns of the tech giant following the death of Steve Jobs in 2011. Also making the list were Supreme Court Justice John Roberts Jr., Bill and Melinda Gates, and Pete Frates, an Advocate for the ALS "Ice Bucket" challenge which became a viral sensation in 2014.

Check out a gallery of the top 20 leaders above. You can see the full list at Fortune's website.