Walter William Horn (18 January 1908 – 26 December 1995) was a German-American medievalist scholar noted for his work on the timber vernacular architecture of the Middle Ages.

Horn was born in Germany, but fled Nazism and spent most of his academic career at the University of California, Berkeley, where he became the university system's first art historian and co-founded the History of Art department. A naturalized citizen of the United States, Horn served in the U.S. Army during World War II and then in the special intelligence unit that tracked down art works plundered by the Nazis. His most celebrated exploit was the recovery of the crown jewels of the Holy Roman Empire, also known as Charlemagne's Imperial Regalia.W. Eugene Kleinbauer, James Marrow and Ruth Mellinkoff, "Memoirs of Fellows and Corresponding Fellows of the Medieval Academy of America: Walter W. Horn," Speculum 71 (1996), p. 800 ("his most important piece of detective work led to the recovery of the coronation regalia of the Holy Roman Empire"); "Walter Horn," San Francisco Chronicle, 30 December 1995, obituary; University of California (System) Academic Senate, "1996, University of California: In Memoriam," "Walter Horn, History of Art: Berkeley" ("his most spectacular feat was the recovery of Charlemagne's ceremonial regalia"). As a scholar, Horn is most noted for his work on the medieval architectural drawing known as the Plan of Saint Gall.

Additions: for recovery of Imperial Regalia, see Sidney D. Kirkpatrick, Hitler's Holy Relics, Simon and Schuster, 2010. Horn was present as a guest of Austria at the reopening of the rooms dedicated to the Reglia at the Hofburg Museum in 1987.

Early life Horn was born in the town of Waldangelloch in rural Baden as Walther Wilhelm Adolf Horn. His mother was Matilde Peters; she married Karl Horn, a Lutheran minister. Walter attended a Gymnasium in nearby Heidelberg and went on to study art history at the University of Heidelberg and the University of Berlin. He earned his doctorate in 1934 at the University of Hamburg, studying under Erwin Panofsky. His dissertation, Die Fassade von Saint-Gilles, on the façade of Saint-Gilles, Gard, was published in 1937.

World War II era

Horn fled Germany in opposition to the Nazi regime. He continued his studies from 1934 to 1937 as a research associate at the German Institute for the History of Art in Florence, Italy. In 1938, Horn moved to the United States and began his long association with the University of California, Berkeley, as a lecturer. A year later, he was given a permanent position as the first art historian in the University of California system.UC In Memoriam, p. 87. During this time, he married Ann Binkley Rand.

Horn became a naturalized citizen in 1943, dropping the forename Adolf because of its associations with the war. That same year, he volunteered for military duty in the U.S. Army. By 1945, he was a lieutenant in the Third Army under General George S. Patton. Horn's skills as a native speaker of German were put to use in interrogating prisoners of war. After the war, he continued as a special investigator in the Monuments, Fine Arts, and Archives program, using his expertise as an art historian to track down art that had been stolen or concealed by the Nazis. Horn served until 1946, attaining the rank of captain.

In 1945, Horn succeeded in recovering the Imperial Regalia of Charlemagne, the crown, sceptre, and jewels of the Holy Roman Empire. These had been kept hidden by Germans who hoped to return to power even after their defeat by the Allies. The incident has been elaborated, sometimes with inaccuracies, by writers who take particular interest in the Holy Lance, the spear supposed to have pierced the side of Jesus during his crucifixion. This artifact is sometimes called the Spear of Destiny and identified with the Vienna Lance, one of the components of the regalia. Horn appears in narratives about the lance's retrieval from the possession of Adolf Hitler in works by occultists and conspiracy theorists. Usually identified as "Lt. Walter William Horn," he is purported to have retrieved the lance at the behest of Patton on the day of Hitler's death, 30 April 1945.See Trevor Ravenscroft, The Spear of Destiny: The Occult Power behind the Spear Which Pierced the Side of Christ (Red Wheel, 1982). Ravenscroft reproduces a portion of Horn's report on the recovery of the regalia (called there "insignia"), p. 348.See E. Randall Floyd, 100 of the World's Greatest Mysteries (Harbor House, 2000), pp. 262–263; Lionel Fanthorpe and Patricia Fanthorpe, Mysteries and Secrets of the Templars: The Story behind the Da Vinci Code (Dundurn Press Ltd., 2005), p. 57.

The McCarthy era Returning from the war, Horn married Alberta West Parker, a physician, who became a Clinical Professor of Public Health at UC Berkeley.San Francisco Chronicle, March 31, 2012, Alberta Horn, obituary In 1949, Horn and his family became embroiled in the controversy at his university over a loyalty oath requirement. During the era of the Cold War, the Red Scare, and McCarthyism, the Board of Regents at the University of California began to require that all university employees sign an oath affirming their loyalty to the state constitution and denying their membership or belief in organizations advocating the overthrow of the U.S. government. The requirement met with resistance, and in the summer of 1950 thirty-one professorsAlong with a number of other employees. who refused to sign were fired, despite their stature as "internationally distinguished scholars."The University Loyalty Oath.

Horn's fellow medievalist Ernst Kantorowicz resigned rather than sign the oath, stating his reasons in two letters to the university president that were only published in English decades after the episode. Kantorowicz also presented a letter from Horn, who had signed the oath under protest. In the letter dated 23 August 1950, Horn, then acting chairman of the art department, pointed to his former military service and to his voluntary reactivation that same month as a reservist in the Armed Services.

Kantorowicz noted that Horn's letter "illustrates the grave conflict of conscience and savage economic coercion to which, after fifteen months of pressure and struggle, he had finally to yield."Horn's letter appears following two letters by Kantorowicz at The University Loyalty Oath: A 50th Anniversary Retrospective, "The Fundamental Issue."

Academic career and scholarship

Horn's early position as research associate in Florence gave him firsthand knowledge of the city's medieval church architecture and produced two important studies, Das Florentiner Baptisterium (1938), an analysis of the fabric and ornamentation of the Florence Baptistry that established new criteria for its dating, and Romanesque Churches in Florence: A Study of Their Chronology and Stylistic Development (1943), which included an examination of the masonry construction of San Miniato al Monte. Throughout his career, he continued to explore the conceptual connections between classical and northern architecture. His specialty was three-aisled timber structures in medieval churches, market halls and manor halls. He was known for arriving at a precise dating of medieval buildings through studying their technologies and observing the physical evidence, drawing on scientific disciplines; he dated timber structures with reference to radiocarbon analysis and dendrochronological tables.Kleinhauer et al., "Memoir," p. 801. See, for example, Walter Horn, "The Potential and Limitations of Radiocarbon Dating in the Middle Ages," in Scientific Methods in Medieval Archaeology, edited by Rainer Berger (Berkeley and Los Angeles, 1970), pp. 23-87.

In 1958, Horn published what is considered his most important article,Kleinhauer et al., "Memoir," p. 800. "On the Origins of the Medieval Bay System" in the Journal of the Society of Architectural Historians. He argued that bay-divided medieval churches derived from Germanic timber buildings and represented a continuous tradition of vernacular architecture in transalpine Europe. Horn was the first to assemble the known timber examples, which dated from as early as 1200 BC and extended into the medieval period. Because traces of early wooden structures were often scanty or oblique, Horn used scientific methods to uncover their architectural principles, and demonstrated that these were developed and applied to stone cathedrals in the Romanesque and Gothic periods.Kleinhauer et al., "Memoir," p. 800; "Walter Horn, History of Art: Berkeley"; Dictionary of Art Historians.

The 1958 article was significant also in that it marked Horn's first collaboration with Ernest Born, the San Franciscan architect and draftsman with whom he was to author a series of books and articles over the next twenty years. Their first book was The Barns of the Abbey of Beaulieu at Its Granges of Great Coxwell and Beaulieu St. Leonard (1965), a study of the only two Cistercian tithe barns, dating from the 13th century, that survive in England. But their major project was the three-volume work The Plan of St. Gall: A Study of the Architecture and Economy of, and Life in a Paradigmatic Carolingian Monastery, which has been called "one of the greatest monographs on medieval architecture that has ever appeared."Kleinhauer et al., "Memoir," p. 801.

Plan of St. Gall

The plan of Saint Gall had engaged Horn's imagination and curiosity since he was introduced to it by his mentor Erwin Panofsky.Kleinhauer et al., "Memoir," p. 800. In 1957, Horn had participated in an international congress on the plan, and his interest in its guest and service buildings led to his survey of medieval structures in France and England. In 1965, Horn and Born contributed to the creation of a scale model of the 40 buildings rendered on the plan. The model was displayed at the international exhibit Karl der Grosse held at Aachen. Their two decades of collaboration culminated in a work of 1,056 pages with an estimated 1,200 illustrations.

The Plan of St. Gall was praised by French historian Emmanuel LeRoy Ladurie for its "prodigious scholarship," and for its wide-ranging elucidation of Carolingian daily life.William Grimes, "Walter Horn, 87, a Historian Of Medieval Cloisters and Barns," New York Times 29 December 1995, obituary The first volume offers a reconstruction of the church and the living quarters for a community of monks numbering about a hundred. The second volume covered the guest and service buildings and the horticultural spaces for growing vegetables, medicinal herbs, and fruit and nut trees. The third volume contains supplemental material such as Horn's 88-page catalogue of the plan's explanatory tituli, or captions, and Charles W. Jones' English translation of the Consuetudines Corbienses by Adalhard of the abbey of Corbie.See Charles W. Jones for more on this collaboration. Through meticulous reimagining of the activities that the architecture was meant to facilitate, Horn presents a rich picture of Carolingian life and thought.

The most controversial aspect of the work was Horn's major thesis: that the plan was a copy of a lost master plan dating to 816 or 817 that would have been part of documents pertaining to the official monastic reform movement under Louis the Pious at Aachen. The dominant strand of criticism to the contrary holds that the plan was intended to represent an ideal and was never meant to be carried out at a particular site. Horn's last article on the plan, "The Medieval Monastery as a Setting for the Production of Manuscripts,"Co-authored with Born in the Journal of the Walters Art Gallery 44 (1986) 16–47. was a response to this criticism.