Muhammad Ali’s death resonated with many of us throughout the weekend, but perhaps it struck a bigger chord with his longtime friend, Bill Russell.

Ali and Russell dominated the 1960s sports landscape and were also key figures in the civil rights movement. So it’s no surprise that the two legendary athletes established a strong bond over the years.

The Boston Celtics legend released a heartfelt statement through the NBA on Sunday morning regarding the death of the boxing icon.

Thumbnail photo via Mark L. Baer/USA TODAY Sports Images