Diehl-Wallendorf was an artist who studied his motifs on site. He was therefore forever traveling around Austria with his sketchpad. He felt particularly attracted to views from Vienna and its environs as well as the landscape of Lower Austria, which greatly inspired him with its variety. Especially atmospheric depictions survive of the Wachau, the Rax region, the Weinviertel and the Vienna Woods.
From 1895, he studied at the Großherzoglichen Akademie der bildenden Künste [Grand Duke’s Academy of Fine Arts] in Weimar under Theodor Hagen. Between 1896 and 1898, he studied under Professor Fridjof Smith and Professor Max Thedy as well as at the Städelsche Kunstinstitut [City Art Institute] in Frankfurt am Main under Professor Marr. While there, he formed a close friendship with Wilhelm Trübner. His study trips took him to Paris, Switzerland, Hungary and Dalmatia. He lived in Vienna from 1906. In the First World War, Diehl served as a painter and interpreter at the front.
As co-founder and president of the artists’ association “Segantini”, he regularly presented his works at their exhibitions between 1920 and 1938. In 1921, Bühne commented on the artists’ association’s spring exhibition: “Represented are, above all, Hanns Diehl-Wallendorf with several large-scale compositions, whose splendid designs and fascinating effects of color and technique reveal an entirely unique and eminently strong and original talent.” Additional exhibitions took place at the Frankfurter Kunstverein [Frankfurt Arts Association) between 1898 and 1901, at the Münchner Kunstverein [Munich Arts Association] in March 1916, in Berlin in 1938 and at the Staatsdruckerei [State Printing Office] in Vienna in 1963.
