This article presents an overview of the career of F. W. Lancaster. It starts with a review of the recognitions he has received for his teaching accomplishments, both in the United States and in many foreign countries. It then turns to his books, for which he has received awards from the American Library Association (ALA) and the American Society for Information Science and Technology, and his other writings, among them the 1969 report on the evaluation of MEDLARS, which received an American Society for Information Science and Technology (ASIS) award as the best paper of the year. Next, Lancaster’s contributions in research are discussed, starting with his work on the evaluation of information systems. Then, Lancaster’s work as consultant to governments, commercial companies, nonprofit agencies, and libraries throughout the world is briefly reviewed. Finally, this article highlights Lancaster’s contributions to the profession, with emphasis on his leadership as editor of Library Trends. The article then concludes by viewing Lancaster’s contributions in the context of historic cooperation between the United States and the United Kingdom.