E T Whittaker was an early 20th century Mathematician. He is credited with pioneering research in special functions. Whittaker was a member of the Royal Society. He was professor of Astronomy at the University of Dublin and Professor of Mathematics at the University of Edinburgh. A Course of Modern Analysis was the first book in English to present the theory of functions of a complex variable at an undergraduate level. This book was instrumental in the study of such functions and their expansions as well as the study of special functions and their related differential equations.