And he told Total Film that he wanted to redress the wrongs that he thinks have been inflicted on the Native American people in cinematic history.
"Since cinema has been around, Native Americans have been treated very poorly by Hollywood," Depp explained. "What I wanted to do was play Tonto not as a sidekick - like 'Go fetch a soda for me, boy!' - but as a warrior with integrity and dignity.
"It's my small sliver of a contribution to try to right the wrongs of the past."
William Fichtner, Tom Wilkinson and Ruth Wilson also feature in the movie, which is set for release on 9 August in the UK.
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