The Kingdom of Poland (, ), also known informally as the Regency Kingdom of Poland (), was a short-lived puppet state of the German Empire and polity that was proclaimed during World War I by it and Austria-Hungary on 5 November 1916 on the territories of formerly Russian-ruled Congress Poland held by the Central Powers as the Government General of Warsaw and which became active on 14 January 1917. It was subsequently transformed between 7 October 1918 and 22 November 1918 into the independent Second Polish Republic, the customary ceremonial founding date of the latter being set at 11 November 1918.

In spite of the initial total dependence of this client state on its sponsors,The Regency Kingdom has been referred to as a puppet state by Norman Davies in Europe: A history ( Internet Archive, p. 910); by Jerzy Lukowski and Hubert Zawadzki in A Concise History of Poland (Google Books, p. 218); by Piotr J. Wroblel in Chronology of Polish History and Nation and History (Google Books, p. 454); and by Raymond Leslie Buell in Poland: Key to Europe (Google Books, p. 68: "The Polish Kingdom... was merely a pawn [of Germany]"). it ultimately served against their intentions in the aftermath of the Armistice of 11 November 1918 as the cornerstone proto-state of the nascent Second Polish Republic, the latter composed also of territories never intended by the Central Powers to be ceded to Poland, and therefore played a crucial role in the resurrection of Polish statehood.

Rationale The decision to propose the restoration of Poland after a century of partitions was taken up by the German policymakers in an attempt to legitimize further imperial presence in the occupied territories and create a buffer state to prevent future wars with Russia. The plan was followed by the German propaganda pamphlet campaign delivered to the Poles in 1915, claiming that the German soldiers were arriving as liberators to free Poland from subjugation by the Russian Empire.Aviel Roshwald. Ethnic Nationalism and the Fall of Empires: Central Europe, the Middle East and Russia, 1914–1923. Routledge, 2002. P. 117. However, the German High Command under Erich Ludendorff also wanted to annex around 30,000 square kilometers of the territory of former Congress Poland, and planned to evict up to 3 million Poles and Jews to make room for German colonists in the so-called Polish Border Strip plan.Immanuel Geiss Tzw. Polski pas graniczny 1914–1918. Warszawa (1964).Elusive Alliance: The German Occupation of Poland in World War I Jesse Kauffman – 2015Military Occupations in First World War Europe Sophie De Schaepdrijver page 69, Routledge, 2015The Great and Holy War: How World War I Changed Religion For Ever Philip Jenkins, page 38, Lion, 2014A State of Nations: Empire and Nation-Making in the Age of Lenin and Stalin Autorzy Ronald Grigor Suny, Terry Martin, page 126, Oxford University Press, 2001 "To wall off this space, German planners discussed establishing an ethnically cleansed border strip in Poland, cleared of all Slavs and settled by ethnic Germans. Ober Ost officials deported large segments of the local population" The German government used punitive threats to force Polish landowners living in the German-occupied Baltic states to relocate and sell their Baltic property to the Germans in exchange for entry to Poland. Parallel efforts were made to remove Poles from the Polish territories of the Prussian Partition.Annemarie Sammartino. The Impossible Border: Germany and the East, 1914–1922. Cornell University, 2010, pp. 36–37.

Planning Germany

With the onset of the war in 1914, for the purposes of securing Germany's eastern border against the Russian imperial army, Theobald von Bethmann Hollweg, the German chancellor, decided on the annexation of a specific strip of land from Congress Poland, known later on as the Polish Border Strip. In order to avoid adding the Polish population to the population of imperial Germany, it was proposed that the Poles would be ethnically cleansed to a proposed new Polish state further east, while the strip would be resettled with Germans.Holborn 1982, p. 449 (see "Sources" section below).Ideology and the Rationality of Domination: Nazi Germanization Policies in Poland, Gerhard Wolf, pp. 29–31, Indiana University Press.

German Emperor Wilhelm II conceived of creating a dependent Polish state from territory conquered from Russia. This new autonomous Kingdom of Poland would be ruled by a German prince and have its military, transportation, and economy controlled by Germany. Its army and railway network would be placed under Prussian command.

In several memoranda sent during 1915 and 1916, Hans Hartwig von Beseler, the Governor-General of the Polish areas under German control, proposed the establishment of an independent Polish state. Under the influence of General Erich Ludendorff, then in effect the director of Germany's eastern European operations, this proposal included the annexation of considerable amounts of land by Germany, Lithuania, and Austria-Hungary. Gerhard von Mutius, the cousin of Chancellor Bethmann Hollweg and the foreign office's representative at Beseler's headquarters, disputed the use of annexation, insisting that "if the military interests allow for it, divisions and secessions should be avoided", as such a policy would secure an "anti-Russian inclination toward the new Poland".

Similar plans were advanced by influential German intellectuals in the early years of the war. Among them were Hans Delbrück, Friedrich Naumann, and Paul Rohrbach. They generally argued that because Polish nationalism and Polish society were so highly developed, Germany would encounter severe resistance if it attempted to annex large territories in Poland. They concluded that Germany could only effectively project power into Poland by establishing an autonomous Polish state as a German protectorate.

The borders of this "autonomous" Poland were to be changed in favour of Germany with the annexation of the so-called "Polish Border Strip", which would lead to the annexation of considerable parts of Polish territory that had been part of the Russian partition of Poland. By the end of 1916, Germany wanted to annex almost 30,000 square kilometres of Polish territory. These lands were to be settled by ethnic Germans, while the Polish and Jewish population was to be removed.

After the expected victory the Polish economy was to be dominated by Germany and preparations were made for German control over the Polish railway system, shipping in the Vistula and industrial areas in Dąbrowa basin, Radom and Kielce.

Such plans were also proposed by members of the German minority in Poland in the Łódź area, who protested the Act of 5th November, and in a letter to the German government demanded the annexation of western Poland by Germany and settlement of ethnic Germans in those areas.Aleksander Kraushar, Warszawa podczas okupacji niemieckiej 1915–1918 , Lwów 1921, p. 39Elusive Alliance: The German Occupation of Poland in World War I page 134 Jesse Kauffman 2015

German candidates for the throne were disputed between the royal houses of Saxony, Württemberg and Bavaria.Tipton, Frank B. A History of Modern Germany Since 1815, p. 312, Bavaria demanded that their Prince Leopold, the Supreme Commander of the German forces on the Eastern front, become the new monarch.Polskie Towarzystwo Historyczne (Polish Historical Society), Przegląd historyczny (Historical Review), volume 60, page 87. An alternative candidate was the then King of Bavaria himself, Ludwig III. The Württemberg candidate Duke Albrechtwas considered suitable for the throne because he belonged to the Catholic line of the house.Tucker, Spencer C. The European Powers in the First World War: An Encyclopedia, p. 34, The claim of the Saxon House of Wettin's candidate Friedrich Christian, was based on three previous Saxon rulers - Electors Augustus the Strong and Frederick Augustus II and King Frederick Augustus I of Saxony - having ruled over Poland before.Craig, Gordon A. Germany: 1866–1945, pp. 358–359, Another candidate was Prince Joachim of Prussia, the sixth son of Kaiser Wilhelm II. Candidates from smaller German houses were proposed; Hans Heinrich XV von Hochberg, Prince of Pless and Prince Kiril of Bulgaria, the second son of Tsar Ferdinand I.

Austria-Hungary

Austria-Hungary allowed the formation of a Polish quasi-government, the Supreme National Committee, and had three different ideas regarding Poland. One, the "Austro-Polish Solution", involved the creation of a Polish kingdom under the Emperor of Austria, who, among his other titles, was already King of Galicia and Lodomeria. German and Magyar (Hungarian) elements within the Habsburg monarchy opposed such a move for fear of creating a predominantly Slavic area. In contrast to Emperor Francis Joseph, Charles I of Austria, who had acceded to the Habsburg thrones in 1916, promoted the idea. Charles was supported by Archduke Wilhelm of Austria, who also backed another Austro-Slavist idea, that of creating an autonomous Grand Duchy of Ukraine within the Habsburg monarchy to counter the German project of Mitteleuropa. The other two ideas involved the division of former Congress Poland between Germany and Austria-Hungary, or between Austria-Hungary and a state built from Lithuania, Belarus and the remnants of Congress Poland to create a new version of the dissolved Polish–Lithuanian Commonwealth.Pajewski 2005, p. 91.

According to Polish historian Janusz Pajewski, "the Austrians had underestimated Germany's desire to determine Poland's fate".Pajewski 2005, pp. 92–93. They did recognise, according to Prime Minister Karl von Stürgkh, that "Poles will remain Poles [...] even 150 years after Galicia was joined to Austria, Poles still didn't become Austrians".Pajewski 2005, p. 93.

Of the candidates for the new Polish throne, Archduke Charles Stephen of Austria () and his son Charles Albert were early contenders. Both resided in the Galician town of Saybusch (now Żywiec) and spoke Polish fluently. Charles Stephen's daughters were married to the Polish aristocrats Princes Olgierd of Czartoryski and Hieronim Mikołaj Radziwill.

By early 1916, the "Austro-Polish Solution" had become hypothetical. Erich von Falkenhayn, the German Chief of the General Staff, had rejected it in January, followed by Bethmann Hollweg in February. Bethmann Hollweg had been willing to see an Austrian candidate on the new Polish throne, so long as Germany retained control over the Polish economy, resources and army.Hein Eirch Goemans 2000, p. 104 (see "Sources" section below).

During the first year of the war, German and Austrian troops quickly conquered Russian Vistula Land, former Congress Poland, and in 1915 divided its administration between a German Governor General in Warsaw and an Austrian counterpart in Lublin. During the German military campaign in the ethnically Polish territory, Poles were subjected to forced labour and confiscation of food and private property.Primary Documents: Speech by Polish Member of Prussian Legislature Regarding German Rule in Poland, 1917; Source: Source Records of the Great War, Vol. IV, ed. Charles F. Horne, National Alumni 1923 Candidates also came from the Polish aristocracy itself, namely Zdzisław Lubomirski, member of the Regency Council, Janusz Franciszek Radziwiłł, and even Josef Pilsudski himself.

Preparations for Polish statehood

Proclamation of two Emperors promising a Polish state