It's incredible to think that the Marvel Cinematic Universe only began five years ago with the first Iron Man. A post-credits cameo by Samuel L Jackson's Nick Fury left fans all over the world with only two words on their mind: 'Avengers Initiative'. As we all know, since then the MCU has gone from nothing but strength to strength. Phase One saw a sequel to Iron Man, rebooted The Incredible Hulk, introduced Captain America and Thor to cinema audiences and culminated in the unprecedented success of The Avengers, which broke box office records around the world on its way to become the biggest film of all time that wasn't directed by James Cameron. Phase 2 also started with a bang as Iron Man 3 became the 5th highest-grossing movie ever, and strong reviews ahead of its opening next week indicate that Thor: The Dark World will continue the studio's run of smash hits. At the time of writing, the Marvel Cinematic Universe has generated over $5 billion in box-office revenue, making it the third biggest franchise of all time behind only Harry Potter and the 50-year-old James Bond series. With that in mind, this article will take a look at the reasons that currently make Marvel the most successful movie studio in the entire industry.