University of Vienna Byzantinist and San Marco scholar. Demus's father, Carl Demus, was a physician. His father was killed early during the First World War and the younger Demus partially supported of his family as an adolescent. He entered the University of Vienna in 1921 during the time of the historic (and bitter) split between the faculty of Josef Rudolf Thomas Strzygowski, and Julius Alwin von Schlosser. The rivalry between these two men was such that studying with both was impossible. Demus chose Strzygowski but steered clear of the wild "pan-Germanic" theories of his mentor. His Ph.D. was granted under Strzygowski cum laude, in 1928. Demus spent the next years personally photographing (in color, using glass plates) Greek Byzantine monuments. In 1931 this collaborative effort with Ernst Diez appeared as Byzantine Mosaics in Greece, one of the first to employ stylistic analysis to the topic. The work was a prelude to the monument which would occupy Demus most of his life, San Marco in Venice. Demus joined the Austrian monument service as a Konservator (curator) in 1930. Though poorly paid and the division poorly organized, Demus worked hard on the inventory and conservation of the medieval monuments in his charge, which included Maria Saal. In 1935 he issued a small volume on San Marco, which solidified his reputation as a scholar. After six years at the monuments service, Demus moved back to the main office in Vienna and, with Habilitation in hand, joined his alma mater where Hans Sedlmayr had succeeded Schlosser. He continued to hold both positions, teaching art history and advising on conservation. With the annexation of Austria by the Nazis in 1938, Demus left, ostensibly for a Byzantine congress in Sicily in 1939, traveling to England for asylum. Demus found employment at the Warburg Library, together with other Austrian and German expatriates. He also lectured at the Courtauld Institute. In 1946 he became president of the office of monuments (Bundesdenkmalamt) in Austria. The following year he issued the slender Byzantine Mosaic Decoration, a synthesis of Byzantine aesthetics and iconography still considered seminal today. The war now concluded and Austria in desperate need of art historians without a recent history of Nazi compliance, Demus was tapped for the newly reorganized Bundesdenkmalamt (Federal Office of Monuments). Though still poorly paid, Demus was given a small house in the Belvedere gardens in which he remained for the rest of his life. He shuttled between Dumbarton Oaks, the newly established Byzantine research center under Harvard University, and Vienna. In 1960, his second title on San Marco appeared, a handbook on every aspect except the mosaics. When Karl Maria Swoboda retired from the University, Demus was offered his chair. However, Demus insisted on the earlier bifurcated arrangement, nominating a Schlosser student, Otto Pächt, to be the "other" chair along with his. The enmity between the two camps during their school days had been so strong that Demus had known of Pächt only through subsequent scholarly publications. In 1963 they began their appointments. Demus relinquished the presidency of the Bundesdenkmalamt in 1964, succeed by Walter Frodl. He issued Romanesque Wall Painting in 1968, which, although a coffee-table-style Hirmer Verlag production, was the result of personal and renewed familiarity with the monuments. The same year he also contributed to the summary volume of the Kariye Djami studies of Paul A. Underwood. He delivered the Wrightsman lectures at New York University (Byzantine Art and the West, 1970), a synthetic view of the influence of both cultures on each other. At age 68, Demus secured Dumbarton Oaks funding to clean the mosaics at San Marco, the necessary step in order for him to write the major work on them. In 1984, the results were published as the two-volume Mosaics of San Marco in Venice. In his eighties, Demus published a final book on the Carinthian (Austria) late gothic carved altarpieces. Demus' students included Irmgard Hutter, who collaborated with him on the Corpus der byzantinischen Miniaturenhandschriften. Hans Belting characterized Demus as one who "obeyed a rigid discipline of scholarship ever since, as a young man, he had to regret the flamboyant lack of responsibility of his teacher, Strzygowski." Mosaics of San Marco in Venice led to several new findings, the most important of which was that eastern dome was the product of two different ventures, one at 1100 and a second nearly a century later when portions of the first had collapsed.
- Otto Demus Papers and the San Marco Mosaics Project and Corpus of North Adriatic Mosaics Papers, Dumbarton Oaks. https://www.doaks.org/research/library-archives/dumbarton-oaks-archives/collections/historical-papers/otto-demus-and-the-san-marco-mosaics-project-papers, Byzantine Studies/Otto Demus, Papers.