Botticelli and Piero di Cosimo scholar. Student of Reinhard Kekulé von Stradonitz. Ullmann studied under Carl Nicolaus Heinrich Justi in the later 1880s at Bonn with fellow students Aby M. Warburg and Wilhelm Vöge. He attended lectures in Munich and was one of the eight students from various universities who attended seminars in Florence in 1889 under August Schmarsow who was attempting to found a German research institute in the city. Ulmann's work was viewed as what was bad about German art historical scholarship by the English-speaking connoisseurs Herbert P. Horne and Bernard Berenson. Erwin Panofsky, borrowing a phrase from Jean Paul, described Ulmann as "without accent" (i.e., undistinguished).
Sandro Botticelli. Munich: Verlagsanstalt für Kunst und Wissenschaft, vormals F. Bruckmann 1893; edited. Bonner Studien: Aufsätze aus der Altertumswissenschaft Reinhard Kekulé zur Errinnerung an seine Lehrthätigkeit in Bonn, gewidmet von seine Schülern. Berlin: W. Spemann, 1890.
mentioned, Pope-Hennessy, John. "Introduction." Horne, Herbert P. Botticelli: Painter of Florence Princeton, NJ: Princeton University Press, 1980, pp. x; mentioned, Panofsky, Erwin. "Wilhelm Vöge: A Biographical Memoir." Art Journal 28 no. 1 (Fall 1968): 29; Gombrich, Ernst H. Aby Warburg: An Intellectual Biography. 2nd ed. Chicago: University of Chicago Press, 1986, p. 39.