Bill Russell, an 11-time National Basketball Association champion and the first black coach for any US professional sports team, died on Sunday. “Bill Russell, the most prolific winner in American sports history, passed away peacefully today at age 88, with his wife, Jeannine, by his side,” his family said in a statement. During his prolific NBA career with the Boston Celtics, Russell won 11 championships, was named in the All-Star team 12 times and was crowned the league's most valuable player five times. He won a gold medal for the US during the 1956 Summer Olympics in Melbourne, Australia. Russell became the first black coach of any North American professional sports team in 1966, when he was announced as a player-coach for his beloved Celtics. He led the team to two NBA titles in 1968 and 1969 as player-coach. Such was Russell's impact on the game that the league dedicated the Finals MVP trophy in his name. “Bill Russell was the greatest champion in all of team sports," NBA commissioner Adam Silver said. "The countless accolades that he earned for his storied career with the Boston Celtics … only begin to tell the story of Bill's immense impact on our league and broader society." Russell's legacy in US sports extends far beyond the parquet floors of TD Garden in Boston. "To be the greatest champion in your sport, to revolutionize the way the game is played, and to be a societal leader all at once seems unthinkable, but that is who Bill Russell was," the Boston Celtics said in a statement. He and other black teammates boycotted a 1961 exhibition game over racial discrimination, led the first integrated basketball camp in Mississippi and thrust his support behind the <a href="https://www.thenationalnews.com/world/the-americas/justice-for-george-floyd-us-cities-rocked-by-protests-over-custody-death-of-black-man-in-minneapolis-1.1026426" target="_blank">Black Lives Matter protests</a> that rocked the US in 2020. Russell, one of the sport's leading civil rights advocates in the 1950s and 1960s, often criticised Boston for its racial strife. In 1963, Russell sat in the front row during Martin Luther King Jr's "I Have a Dream" speech in Washington. Former president Barack Obama, who awarded the Presidential Medal of Freedom to Russell in 2011, said "we lost a giant". "For decades, Bill endured insults and vandalism, but never let it stop him from speaking up for what’s right. I learned so much from the way he played, the way he coached, and the way he lived his life," Mr Obama said in a tweet. Russell was inducted into the NBA Hall of Fame twice — as a player and as a coach.