Tony Benn and Sir Willard White were among the speakers and performers at the unveiling of a plaque at School of Oriental and African Studies to honour Paul Robeson.
Robeson studied phonetics and Swahili at the school. He was an athlete, actor, singer and Communist activist.
At the well attended event speakers recounted how Robeson, the son of a slave, was one of the towering figures of the 20th century.