On May 2nd, 2008, Iron Man was released. Still considered a B-List superhero at the time, no one had particularly high expectations, but impressive trailers - with some game-changing special effects - certainly helped increase interest. With Robert Downey Jr. in a leading role and a supporting cast made up of names like Gwyneth Paltrow and Terrence Howard, no one was entirely sure what to expect, but reviews were positive and an incredible opening weekend followed.
After grossing $3.5 million during opening night previews on May 1st, Iron Man scored a $35.2 million opening day and an amazing weekend haul of $98.6 million (which may seem small by today's standard but, at the time, was the eleventh biggest opening weekend of all-time).
Ultimately, Iron Man would go on to gross $585 million at the worldwide box office, a number which ensured that a sequel was released two years later. Later that same year, though, The Incredible Hulk smashed its way into theaters, but the contrast between the two films was significant. Reviews weren't anywhere near as positive for the Jade Giant's return to the big screen, and it only grossed $264.8 million by the time all was said and done.
Luckily, the Armoured Avenger's first solo outing was successful enough to ensure that the Marvel Cinematic Universe would continue, and work continued in earnest on films for characters like Captain America and Thor. The original plan was to release The Avengers in 2011, and while that idea was ultimately changed as the first wave of stories in what would become known as the "Infinity Saga" developed, Iron Man remained a focal point of this shared world. Downey even appeared in The Incredible Hulk's post-credits scene, setting the stage for a version of The Avengers that was going to see the team battle The Hulk.
As the years passed, Iron Man became the character these stories revolved around and a box office draw in a way no one could have ever imagined. However, as Kevin Feige himself has said, "I thought they all had amazing potential, but the goal was deliver these two movies, and make the best Iron Man film we could, and make the best version of Hulk. It wasn't, 'This is the first of a 22-movie cinematic saga.'"
The appearance of Nick Fury and mention of the "Avengers Initiative" ensured it would be, though, and even all these years later, no studio has managed to create a cinematic universe anywhere near as successful as this one.