The most popular films currently belong to Marvel Studios; four of their films, including The Avengers, Iron Man 3, and Captain America: Civil War, have grossed over a billion dollars worldwide.
It has since been confirmed that both films are being retitled accordingly, the first part being called Avengers: Infinity War, while the second remains as an untitled Avengers film.
Recently, Joss Whedon, director of the first Avengers film, said he would return to Marvel to direct a Black Widow film (if the studio ever get round to making one).
Following the likes of upcoming releases Doctor Strange, Guardians of the Galaxy Vol. 2, and Black Panther, the third and fourth Avengers films will hit cinema screens, the two films previously titled Infinity War Parts 1 and 2.