Six Phases of the Marvel Universe

World War II (Captain America 1)

The first stage

The second stage

Iron Man reveals his identity until the end of The Avengers 1 (about 2008-2012)

The third stage

After The Avengers 1 to before The Avengers 2 (about 2012-2015)

The fourth stage

After Avengers 2 until the end of the Civil War in Captain America 3 (around 2015-2016)

The fifth stage

After the Civil War until before Avengers 4 (around 2016-2018)

The sixth stage

The six phases of the Marvel Universe