After the intermission of the Temporary Committee of the Provisional Council of State (), the Central Powers introduced a provisional constitution, the "patent", on 12 September 1917. The "patent" devised a constitutional monarchy with a bicameral parliament but without ministerial responsibility. Only schools and courts were transferred to Polish authorities, but — under Polish protests — the German minority was given a separate school system. Pending the election of a King of Poland, a Regency Council () was installed as a provisional government. On 18 September, the following members of the Council were named: Aleksander Kakowski, Archbishop of Warsaw; aristocrat Prince Zdzisław Lubomirski who had served as mayor of Warsaw in 1916/17; and Józef Ostrowski, a great landowner and formerly the leading Polish politician in the Russian Duma.