Born in Vienna to a factory owner, Basel studied at the Wiener Kunstgewerbeschule under Felician von Myrbach between 1892 and 1898. He was a reserve officer during the First World War, serving with the rank of "Oberleutnant" in the Fourth Army on the Galician front from March 1915. In the fall he fell ill and was declared unfit for military service. By November he was a war artist serving the Kriegspressequartier. In 1916 he was on the Vistula, in the Carpathians, in Albania, on the Isonzo, and in the Ukraine. It was his artistic breakthrough.