This week avid Avengers fans will flock to the movie theatre to catch the latest installment in the franchise, Avengers: Infinity War. The action-packed superhero flick is set to be the highest-grossing movie of the year, if not of all time.

It is set to be true Marvel mayhem, with just about every character from every franchise within the Marvel Cinematic Universe coming through to help save the day – or, just make things worse.

For the first time, this superhero film doesn’t look like it’ll end with a happily ever after. Watch the trailer here…

But whilst the cast may look ready to challenge Thanos as he comes in search of the Infinity Stones, it hasn’t always been that way. If he’d have come to Earth several years ago, he’d have been able to rule it within seconds, because this bunch certainly wouldn’t have been able to stop him…

1. Chris Evans as Captain America

Chris Evans first flaunted his toned torso on the big screen back in 2005 when he brought Marvel’s Johnny Storm/The Human Torch to life in Fantastic Four and its later sequel.

Clearly not content with just two films featuring the buff Boston-native, Marvel signed Evans up for the role of a lifetime when they cast him as Captain America

Of course, there was a drastic difference between the self-assured and vain Johnny Storm and the patriotic, genetically-modified Steve Rogers, so Evans had to hit the gym – hard.

Luckily, the 36-year-old is “a big fan of working out”, so getting stacked for the role came naturally – the paycheck can’t have hurt either!

2. Robert Downey Jr. as Iron Man

When Robert Downey Jr. was cast as Tony Stark, aka Iron Man, he had a lot to prove. With an early career marred by drug abuse and stints in prison, Downey needed to prove his bankability for Marvel Studios given that they were trusting him to lead the first film in their cinematic universe.

Thankfully, the 53-year-old actor didn’t let them down. In fact, Iron Man was such a success that a further two films followed. He also became one of the central figures in the following Avengers films – so it’s no wonder Forbes listed him as the highest-paid actor in Hollywood for 2015.