On 13 March 1938, Bürckel was appointed acting head of the Party to carry out the referendum on the Anschluss (Austria's absorption into Germany). From 23 April 1938 to 31 March 1940, he worked as Reichskommissar for the union of Austria with the German Reich, in charge of fully integrating it as the Ostmark politically, economically and culturally into the latter. He declared: "This is a revolution.