The world is mourning the tragic, unexpected death of Chadwick Boseman, who passed away from colon cancer at the age of 43 on August 28. The actor, who kept his diagnosis and fight under wraps, was diagnosed with stage III colon cancer in 2016--meaning that he was fighting his own private battle during the filming of Black Panther, Avengers: Infinity War and Endgame, and his non-Marvel work during this period.

　　Ryan Coogler, who directed Boseman in Black Panther, has penned a moving tribute to the actor on Marvel's website, where he praises Boseman not just for his performance, but for his humanity, his creativity, and his kindness.

　　Coogler discusses how he "inherited" Boseman's casting from Captain America: Civil War, saying that this is "something that I will forever be grateful for." He recalls seeing Boseman's performance in an unfinished cut of the movie, and how it convinced him to come on and do Black Panther. "I’ll never forget, sitting in an editorial suite on the Disney Lot and watching his scenes," he writes. "His first with Scarlett Johansson as Black Widow, then, with the South African cinema titan, John Kani as T’Challa’s father, King T’Chaka. It was at that moment I knew I wanted to make this movie."

　　Coogler recalls how Kani and Boseman held a discussion in Xhosa, Kani's native language, which he says "had a musicality to it that felt ancient, powerful, and African." He learned that Boseman, who didn't speak Xhosa, had made the decision to learn his lines in an African language. "I couldn’t conceive how difficult that must have been, and even though I hadn’t met Chad, I was already in awe of his capacity as actor," Coogler recalls.

　　Xhosa went on to be the official language of the fictional nation of Wakanda, and Boseman famously advocated for T'Challa to speak in an African accent. As Coogler puts it, "he could present T’Challa to audiences as an African king, whose dialect had not been conquered by the West."

　　Coogler recalls meaning Boseman for the first time in 2016, when the actor visited him during a press junket for his earlier film, Creed. "We spoke about the irony of how his former Howard classmate Ta-Nehisi Coates was writing T’Challa’s current arc with Marvel Comics," Coogler recalls. "And how Chad knew Howard student Prince Jones, whose murder by a police officer inspired Coates’ memoir Between The World and Me."

　　"I noticed then that Chad was an anomaly," he continues. "He was calm. Assured. Constantly studying. But also kind, comforting, had the warmest laugh in the world, and eyes that seen much beyond his years, but could still sparkle like a child seeing something for the first time."

　　Coogler says that it was Boseman who best recognized what the film could be, saying on the set "This is Star Wars, this is Lord of the Rings, but for us." Coogler reflects back on this now and sees the truth in Boseman's words. "I had no idea if the film would work. I wasn’t sure I knew what I was doing. But I look back and realize that Chad knew something we all didn’t. He was playing the long game. All while putting in the work. And work he did."

　　Coogler says that he "wasn't privy" to Boseman's illness, and was as shocked as the rest of us about his passing. "After his family released their statement, I realized that he was living with his illness the entire time I knew him," Coogler says. "Because he was a caretaker, a leader, and a man of faith, dignity and pride, he shielded his collaborators from his suffering. He lived a beautiful life. And he made great art. Day after day, year after year. That was who he was. He was an epic firework display. I will tell stories about being there for some of the brilliant sparks till the end of my days. What an incredible mark he’s left for us."

　　Coogler ends his statement with an extremely moving sentiment. "In African cultures we often refer to loved ones that have passed on as ancestors," he writes. "Sometimes you are genetically related. Sometimes you are not. I had the privilege of directing scenes of Chad’s character, T’Challa, communicating with the ancestors of Wakanda. We were in Atlanta, in an abandoned warehouse, with bluescreens, and massive movie lights, but Chad’s performance made it feel real. I think it was because from the time that I met him, the ancestors spoke through him."

　　"It’s no secret to me now how he was able to skillfully portray some of our most notable ones," Coogler continues. "I had no doubt that he would live on and continue to bless us with more. But it is with a heavy heart and a sense of deep gratitude to have ever been in his presence, that I have to reckon with the fact that Chad is an ancestor now. And I know that he will watch over us, until we meet again."

　　Coogler has spent the previous year working on the script for Black Panther II. In the initial statement by Boseman's family announcing the actor's passing, they noted that "It was the honor of his career to bring King T'Challa to life in Black Panther."

　　Chadwick Boseman's final performance will be in Ma Rainey's Black Bottom, coming to Netflix this year. He's also in Spike Lee's latest joint, Da 5 Bloods, released earlier this year. For Black Panther, Boseman won Outstanding Actor at the Black Reel Awards, Outstanding Actor at the NAACP Image Awards, Best Performance in a Movie and Best Hero at the MTV Movie + TV Awards, Favorite Male Movie Star at the People's Choice Awards, and a cast ensemble award at the Screen Actors Guild Awards.