The Marvel Cinematic Universe is a work.
The Marvel Cinematic Universe ( MCU ) is an American media franchise and shared universe that is centered on a series of superhero films , independently produced by Marvel Studios and based on characters that appear in publications by Marvel Comics . The first film released in the MCU was Iron Man ( 2008 ) , which began the first phase of films culminating in the crossover film Marvel 's The Avengers ( 2012 ) .