Civil rights activist Vincent Harding, one of Martin Luther King Jr's advisers, has died aged 82.
Denver's Iliff School of Theology, where he taught for many years, said Dr Harding died at the Hospital of the University of Pennsylvania on Monday.
Dr Harding first met Dr King when he travelled from Chicago to Atlanta to work in the movement.
He later served as the first director of what is now known as the King Centre, established in Atlanta after Dr King's death by his widow to further their wor
Tributes posted on Twitter called him a "great figure in the African American freedom struggle":
Greatly saddened by the passing today of Vincent Harding, a great figure in the African American freedom struggle. http://t.co/0pNLOxhW4x
Dr. Vincent Harding has passed. RIP. What a life. What a journey. What an amazing teacher. My sympathy to his family & friends. #CoPoltics
Rest in Peace Dr. Vincent Harding. Brother, mentor and friend http://t.co/h6v8lQivAE
Celebrating the incredible life & legacy of Vincent Harding today. May we "dream of worlds that do not yet exist"! http://t.co/UgbvZQr7zq