Karl Renner
After the 1918 assembly had elected the Social Democrat Karl Renner state chancellor, the Christian Social Party formed a grand coalition with the SDAP under Karl Seitz. In the 1919 Austrian Constitutional Assembly election, the CS gained 35.9% of the votes cast, making it again the second strongest party after the Social Democrats. With its support the assembly enacted the Habsburg Law concerning the expulsion and the takeover of the assets of the House Habsburg-Lorraine. On 10 September 1919, Chancellor Karl Renner had to sign the Treaty of Saint-Germain, which prohibited any affiliation with Germany. It was ratified by the assembly on 21 October.