Lars Ahlfors often spoke of his excitement as a young student listening to Rolf Nevanlinna's lectures on the new theory of meromorphic functions. It was, as he writes in his collected papers, his "first exposure to live mathematics." In his enormously influential research papers and in his equally influential books, Ahlfors shared with the reader, both professional and student, that excitement. The present volume derives from lectures given at Harvard over many years, and the topics would now be considered quite classical. At the time the book was published, in 1973, most of the results were already decades old. Nevertheless, the mathematics feels very much alive and still.
