Iron Man is a fictional comic book superhero in the Marvel Comics universe. Iron Man was originally an anti-communist hero. Throughout the character's comic book series, technological advancement and national defense were constant themes, but later issues developed Stark into a more complex and vulnerable character as they depicted his battle with alcoholism and other personal difficulties. Writers often portray Iron Man as a symbol of humanity's creativity as well as its frailties. Throughout most of his career, Iron Man has been a member of the superhero team the Avengers. He has been adapted into animated films and TV series, as well as live-action films.