Holbein scholar and professor of art history at the University in Basel, 1909-. Ganz father was Rudolf Ganz (1848-1928) the portrait photographer. He studied at the Académie des beaux-arts in Brussels between 1890 and 1892 and then the history of art at the University in Zürich. His first appointment was at the Musée historique in Basel, 1900-1901, then a privatdozent 1901. Between 1902 and 1919 he was conservator of the public art collections (öffentliche Kunstsammlung). In 1909 Ganz was appointed professor of art history at the University in Basel. The following year he married Cécile Kern. In 1913 he founded the Jahrbuch für Kunst und Kunstpflege in der Schweiz, an annual. Ganz hired the new Ph.D. Joseph Gantner to be his assistant in 1920 at the University, who later became professor there. He became ordinarius in 1929. Ganz was part of the group founding the Archives suisses d'histoire de l'art. Ganz built a significant personal art collection, which included a Turner and a Tintoretto as well as works by the Swiss artist Ferdinand Hodler. He reorganized the Society of Art History in Switzerland. In 1937 he made an extended trip to the United States, lecturing on Holbein and examining the considerable holdings in the country. He issued the catalogue raisonné on Holbein in 1950. Ganz was a member of the Pro Helvetia committee. His son, Paul Leonhard Ganz (1910-1976), was also an art historian and edited his father's books after his death.Ganz specialized in the English émigré masters of his own country, Fuseli and Holbein. His catalogue raisonné was considered by the Holbein scholar John Rowlands in 1985 to be one of the three important catalogues on the artist.
Meisterwerke der öffentlichen Kunstsammlung in Basel. Munich: F. Hanfstaengl, 1924; Die Zeichnungen Hans Heinrich Füsslis (Henry Fuseli). Bern: Urs Graf-Verlag, 1947, English, The Drawings of Henry Fuseli. New York: Chanticleer Press, 1949; Hans Holbein: die Gemälde. Basel: Birkhäuser, 1950, English, The Paintings of Hans Holbein London, Phaidon, 1950; and Ganz, Paul Leonhard. Geschichte der Kunst in der Schweiz von den Anfängen bis zur Mitte des 17. Jahrhunderts. Basel: B. Schwabe 1960.
mentioned, Sitt, Martina, ed. Kunsthistoriker in eigener Sache: Zehn autobiographische Skizzen. Berlin: D. Reimer, 1990, pp. 140; Historisches Lexikon der Schweiz http://www.hls-dhs-dss.ch/index.php, cite 1045; [obituary:] Werk 41 (November 1954): 270.