Renaissance sculpture specialist, chairman and professor of the department of art, New York University, 1949-1979; wrote the famous survey of art history. Janson was born to Friedrich Janson (1875-1927) and Helene Porsch (Janson) (1879-1974). His parents were of Swedish and Latvian extraction living in Russia. The family moved to Hamburg after the Russian Revolution, where Janson graduated from the Wilhelms Gymnasium in 1932. He studied at Munich and then at the new art history program at the university in Hamburg where he was a student of Erwin Panofsky. He was a part of the so-called Hamburg school of art history whose other students included William S. Heckscher, Lotte Brand Foerster, and Klaus Hinrichsen (b. 1927) and Liselotte Müller. In 1935, at the suggestion of Panofsky, who had fled Germany in 1933 for the United States, Alfred H. Barr, Jr., director of the Museum of Modern Art in New York, sponsored Janson as an immigrant to the United States where he had been awarded a Charles Holtzer fellowship at Harvard University. Janson studied at Harvard between 1935-1942 under Chandler R. Post and Paul J. Sachs. He became close and lifelong friends with fellow Harvard art-history student Sydney Joseph Freedberg. Janson worked at the Worcester Museum of Art, Worcester, MA, 1938, while pursuing his graduate degree and then at the University of Iowa, 1938-1941. According to his son, Anthony, Janson drew the ire of the chairman of the Iowa department of art, the painter Grant Wood, for taking art students to see a Picasso show in Chicago. In 1941 he left Iowa for Washington University in St. Louis, MO, and an assistant professorship, marrying Dora Heineberg, an art-history undergraduate at Radcliffe, the same year. His Ph.D. was awarded from Harvard in 1942 on the subject of Michelozzo. His family remained in Germany during World War II, where his brother, fighting for the Nazis, was killed in 1943. During World War II, when many universities had been converted to soldier training camps, Janson lectured on physics and Russian to American soldiers in St. Louis. He became a citizen in 1943. In 1946 he was appointed associate professor of art history.
Janson left Missouri for New York in 1949 where he was appointed professor and chairman of the department of art at New York University. He remained chair for twenty-five years, developing the undergraduate (Washington Square) program into one of the finest in the nation. He was adjunct faculty at the Institute of Fine Arts, the graduate program at NYU, though frictions developed between the graduate faculty and Janson. He was awarded a Guggenheim fellowship for 1952-1953. That same year he published Apes and Ape Lore in the Middle Ages and the Renaissance, for which he was a recipient of the Charles Rufus Morey Prize from the College Art Association. In 1957, using the initial work of the late Jenö Lányi, Janson published a book on Donatello, The Sculpture of Donatello, which was again awarded a Morey Prize from the College Art Association. In 1959. Janson issued a book of plates of the monuments of art history, titled Key Monuments of the History of Art, to aid his undergraduates in their student of art since the availability of good personal study images was not then available. He followed this in a work co-written with his wife, Dora, with a survey of Western art, their History of Art. It grew over the years to be the best-selling textbook of any subject in the United States and, known simply as "Janson," was for years was the standard text. Janson's interests turned to nineteenth-century art in later years. In 1974 Janson delivered the Mellon lectures at the National Gallery of Art in Washgington, D. C. on 19th-century sculpture. Together with Peter Fusco (b. 1945), he organized a show of that era sculpture for the Los Angeles County Museum of art in 1980. Janson was awarded an honorary doctorate from the Institute of Fine Arts in 1981. He was working on revisions of his Mellon lecture for a book at the time of his death on a train between Italy and Switzerland.
Janson built the (undergraduate) art history department of New York University to the eminence it enjoys today, hiring Jane Costello, Anne Coffin Hanson, Isabelle Hyman, Sarah Landau, Lavin, Robert Rosenblum, Lucy Freeman Sandler, Gert Schiff, Marvin Trachtenberg, and Guy Walton. He was one of the first to hire a significant number of female art historians at a time when teaching faculty in art history were, outside of women's colleges, largely male. Because Janson's appointment at NYU was primarily at the undergraduate level, he had few Ph.D. students compared to others of his profile at the University. His students (at Washington University) included Irving Lavin and Marilyn Aronberg Lavin. Janson's work, especially his Ape lore book, show the influence of the Hamburg school/Warburg influence. The book focuses on the history of art or styles as much as it does mythological phenomenon and its manifestation in material culture. Janson 1962 History of Art was an instant best seller, contrasting it from the other predominant art-history text, Art Through the Ages by Helen Gardner, which by its numerous posthumous revisions treated art as a history of styles. Janson's book came under criticism in later years for its lack of any women artists. Subsequent editions written by his son, Anthony F. Janson (b. 1943), altered this.
- White, John. "H W Janson." The Burlington Magazine 125, no. 961. (April 1983): 226;
- Russell, John. "Prof. H.W. Janson Is Dead at 68, Wrote Best-Selling 'History of Art'." New York Times October 3, 1982, p. 44.
- Kleinbauer, W. Eugene. Modern Perspectives in Western Art History: An Anthology of 20th-Century Writings on the Visual Arts. New York: Holt, Rinehart and Winston, 1971, p. 65,
- cited; Bazin, Germain. Histoire de l'histoire de l'art; de Vasari à nos jours. Paris: Albin Michel, 1986, p. 543;
- Wendland, Ulrike. Biographisches Handbuch deutschsprachiger Kunsthistoriker im Exil: Leben und Werk der unter dem Nationalsozialismus verfolgten und vertriebenen Wissenschaftler. Munich: Saur, 1999, vol. 1, pp. 332-8;
- Janson, Anthony. "Janson, Horst Woldemar" American National Biography;
- About DAH NYU Department of Art History and "Masters of the Third Floor: NYU Art History Documentary." (video) https://as.nyu.edu/content/nyu-as/as/departments/arthistory/about.html