This book tells the story of the Finnish-American mathematician Lars Ahlfors (1907-1996). He was educated at the University of Helsinki as a student of Ernst Lindelof and Rolf Nevanlinna and later became a professor there. He left Finland permanently in 1944 and was professor and emeritus at Harvard University for more than fifty years. Already at the age of twenty-one Ahlfors became a well-known mathematician having solved Denjoy's conjecture, and...