Born in St. Louis, he was raised in Mexico, Mo., and attended Governor Dummer Academy (now The Governor’s Academy) in Byfield, Mass. At Princeton, Allen was a member of Cottage and majored in art and archaeology. He roomed with T. Rourke his senior year.
After Princeton, Allen earned a Ph.D. in art history at Yale. He went on to hold curatorial positions at the Frick Collection in New York and the Philadelphia Museum of Art before joining the faculty of Columbia University. He taught at Columbia for more than 30 years, serving as department chair and inspiring generations of students to pursue studies in art history.
Allen was the author of five books on British art, including The Pre-Raphaelite Landscape and Pre-Raphaelite Vision: Truth to Nature. Allen’s scholarship into the Pre-Raphaelites helped renew interest in the once-obscure movement, leading to a major reappraisal of the period. He also co-wrote the definitive work on the early American artist Benjamin West.
After retiring, Allen continued to write books and scholarly articles while splitting time between New York, London, and a country home in Amenia, N.Y.
He is survived by his wife of 55 years, Etheleen Staley; their sons, Oliver and Peter; and four grandchildren.