George F. R. Ellis is as widely respected for his antiapartheid Quaker activism as for his contributions to cosmology. For the past decade, he has been a professor of applied mathematics at the University of Cape Town while lecturing throughout the world. He is a fellow of the Royal Astronomical Society and the Institute of Mathematics and its Applications. The many prizes he has been awarded include the Star of South Africa Medal, which was presented to him in 1999 by President Nelson Mandela. Coauthor with Stephen W. Hawking of The Large Scale Structure of Space Time (1973), he has also written more than two hundred scientific papers and eight major books.