Cornelis ("Kees") Zwaan was a well-known solar physicist at Utrecht University in The Netherlands. Together with his graduate students he also ventured out to other cool stars, concentrating on their magnetic activity. He has been a member of the AAS and the Solar Physics Division and had close ties with many American astro-physicists. He died from cancer in his house at Doorn, The Netherlands on June 16, 1999. He had had major surgery in 1998, but recovered so fast that we and his other friends expected to have him with us much longer. The end came far too soon.