The Marvel Cinematic Universe is a media franchise and shared fictional universe that is the setting of superhero films produced by Marvel Studios, based on characters that appear in Marvel Comics publications. Phase One of the franchise includes six films, featuring four different superhero properties, leading up to a crossover in the 2012 film Marvel's The Avengers. The franchise's Phase Two features three sequels to Phase One films, as well as two new film properties, and the crossover Avengers: Age of Ultron, which released in 2015. Phase Three features four sequels to earlier films, and four new film properties, as well as the crossover films Avengers: Infinity War (2018) and Avengers: Endgame (2019). The films from Phase One through Phase Three are collectively known as "The Infinity Saga".