Donald Kagan was the Sterling Professor Emeritus of Classics and History at Yale University. His four-volume History of the Peloponnesian War is the leading scholarly work on the subject. He was also the author of many books on ancient and modern topics, including On the Origins of War and the Preservation of Peace, The Great Dialogue: A History of Greek Political Thought from Homer to Polybius, and Thucydides: The Reinvention of History.

A former dean of Yale College, he received his Ph.D. in 1958 from The Ohio State University.  Professor Kagan won numerous awards and fellowships, including four teaching awards at Cornell and Yale. In 2002 he was the recipient of the National Humanities Medal, and in 2005 was named the National Endowment for the Humanities Jefferson Lecturer.