Alexander Rothaug received his training from 1885 to 1892 at the Academy of Fine Arts in Vienna, where he was particularly inspired by the oriental painter Leopold Carl Müller. He then went to Munich and worked there, among other things. as an illustrator for "Fliegende Blätter".

After his travels, which took him to Italy, Spain and Dalmatia, Rothaug returned to Vienna in 1910, where he became a member of the Künstlerhaus. His pictures, which are often pure color frenzy, reveal the longing for antiquity and mythology. Many Rothaug's motifs refer to the dreamlike visionary or fairytale-like.

Alexander Rothaug began to serve an apprenticeship as a sculptor in 1884, which he gave up only a year later to study painting at the Academy of Fine Arts in Vienna. After his studies Rothaug moved to Munich for several years, working for the satirical magazine Fliegende Blätter (Flying Leafs).

In 1897 he returned to Vienna as a freelance painter. Among other things he also worked as a stage designer and frequently went on educational trips, especially in Southern Europe. He began to regularly exhibit his works and created several monumental ceiling and wall paintings based on his experiences as a stage painter. Today his works are mostly found in private collections.