Since the Marvel Cinematic Universe was launched in 2008, continuity has become a huge part of how Marvel Studios tells stories, and there's really no one better out there at creating a working shared world than Kevin Feige. However, mistakes have been made over the years, and that's forced the MCU to make some huge retcons to set things right.
It's not just a case of making up for past errors either, as the way the MCU has unfolded over the years has forced Marvel Studios to change tact and explain away what once appeared to be key subplots.
That was particularly prevalent in this cinematic universe's early days, especially in the build up to 2012's The Avengers. There are plenty of examples since then, though, and some are actually just pretty fun and haven't necessarily been done to set the stage for future stories or explain away ones that didn't ultimately happen.
With that in mind, this feature takes a look at the biggest, craziest, and most unexpected retcons which have been made by Marvel Studios from Iron Man right up until Avengers: Endgame last year. These were definitely unexpected, and it's hard not to wonder about what might have been had they panned out...