In 1909 he started what was to become a 20-year partnership with Franz Arnold with whom he wrote more than 20 plays, mainly farces and operettas. Their first hit play was The Spanish Fly in 1913.
In 1903 he moved to Berlin to the Residenztheater, then to Lustspielhaus in 1905, where he became Regisseur (Director) in 1906 and in 1908 Oberregisseur.
He was an Austrian actor and playwright.
Ernst Bach and Franz Arnold went on to become one of the leading play writing teams in Weimar Germany.
In 1917 he became the director of the Muenchener Volkstheater in Munich, whilst continuing his writing partnership with Franz Arnold at Starnberg. He remained in Munish until his death in 1929.
He made his debut as an actor at the Wiener Raimond Theater in 1899.