Black Panther actor Chadwick Boseman has died of colon cancer at the age of 43.
He had been battling the illness for four years but hadn't spoken about it publicly.
In a statement, Boseman's family said: "A true fighter, Chadwick persevered through it all, and brought you so many of the films you have come to love so much.
"It was the honour of his career to bring King T'Challa to life in Black Panther."
— Chadwick Boseman (@chadwickboseman) August 29, 2020
Boseman had played icons like James Brown and Jackie Robinson in films in the 2010s, before finding global fame as King T'Challa in the Marvel series.
Black Panther earned more than $1.3 billion globally, with Boseman returning to the role in the two most recent Avengers films.
Earlier this year he also appeared in the Spike Lee film Da 5 Bloods, and he also played the lead role in 2019's 21 Bridges.
A number of Boseman's Avengers co-stars and collaborators were among those who paid tribute to the actor.
Angela Basset, who played the mother of Boseman's character in Black Panther, said: "It was meant to be for Chadwick and me to be connected, for us to be family.
"This young man’s dedication was awe-inspiring, his smile contagious, his talent unreal.
"So I pay tribute to a beautiful spirit, a consummate artist, a soulful brother."
Mark Ruffalo, who plays Bruce Banner / The Hulk, said: "All I have to say is the tragedies amassing this year have only been made more profound by the loss of Chadwick Boseman.
"What a man, and what an immense talent. Brother, you were one of the all time greats and your greatness was only beginning. Lord love ya. Rest in power, King."
Marvel Studios, meanwhile, said the actor's legacy will "live on forever".
Our hearts are broken and our thoughts are with Chadwick Boseman’s family. Your legacy will live on forever. Rest In Peace. pic.twitter.com/DyibBLoBxz
— Marvel Studios (@MarvelStudios) August 29, 2020