After congress Poland and western Galicia, most of the province of Posen and in the spring also eastern Galicia and the north-eastern districts as far as Vilnius could be occupied by military forces. It was thanks to the work of Prime MinisterPaderewski and Dmowski that Poland, in the Treaty of Versailles, had almost all of Poznan and large parts of West Prussia left the Vistula (Polish Corridor) and plebiscites were to be held in the disputed areas around Allenstein, Marienwerder and in Upper Silesia. While Poland received only a few votes (2.2% and 7.6% respectively) in the votes in southern East Prussia and in West Prussia on the right of the Vistula, on March 20, 1921 in Upper Silesia 40.4% voted in favor of joining Poland. Even the last of the three Polish uprisings in May 1921 could not prevent the division of Upper Silesia by the League of Nations, whereby Poland received the coal-rich and industrial-rich smaller eastern part with Katowice and Königshütte. The elevation of Danzig to the status of “Free City” (1920) put a strain on German-Polish relations. In the dispute with Czechoslovakia, the district of Teschen became divided along the Olsa. After Piłsudski had rejected the Curzon Line as the Polish eastern border, he triggered the Polish-Soviet war with the Polish offensive (April 1920). In the Peace of Riga (March 18, 1921) the opponents of the war agreed on a Polish-Russian border about 150 km east of the Curzon Line. With a military campaign (1920) General Lucjan Żeligowski (* 1865, † 1946) brought the Wilna area under Polish sovereignty. According to estatelearning, Poland now covered an area of around 388,000 km2 with over 27 million residents (but only just under 19 million of Polish ethnicity).
The task of bringing together four different administrative, legal, financial, transport and educational systems as well as eliminating social and economic imbalances overwhelmed the frequently changing governments of Poland. The relationship with the national and religious minorities was heavily strained, as Poland saw itself as a nation-state, although non-Polish minorities made up about 31% of the total population. The constitution passed on March 17, 1921, based on the French model, provided for a bicameral parliament, the Sejm with 444 members and a Senate limited to 111 members. Since the president had few rights and the elections in November 1922 did not result in clear majorities, Piłsudski ran not for this office, which was held by the socialist Stanisław Wojciechowski (* 1869, † 1953) after the murder (December 16, 1922) of Gabriel Narutowicz (* 1865, † 1922). With the introduction of the zloty, the currency was consolidated; In 1925 an agrarian reform started at the expense of the large estates. Against the background of bad harvests, serious unemployment, corruption, disputes over offices, v. a. but in view of a deterioration in the foreign policy situation, Piłsudski carried out a coup on May 12, 1926. While maintaining the constitution and the democratic structure of the state, supported by his extraordinarily great authority among the population and the loyalty of the armed forces, he began his “moral dictatorship.”
The left’s initial willingness to cooperate turned into enmity when Piłsudski approached the ruling class from the nationally mixed eastern regions and a bloc of cooperation with the government (BBWR) founded by his confidante Walery Sławek (* 1879, † 1939) replaced the previous spectrum of parties began to break up. In the fall of 1930, the opposition, which had formed the Center Left (Centrolew), was broken up in breaches of the law and after arrests, and its leaders were forced to emigrate. With the help of an enabling law (March 23, 1933) on April 23, 1935 one on Piłsudski tailored authoritarian constitution to be adopted. But with his death on May 12, 1935, due to the mediocrity of his successors, who soon paralyzed themselves in diadoch battles – President I. Mościcki, Commander-in-Chief E. Rydz-Śmigły, Foreign Minister J. Beck - the system that had previously been shaped by Piłsudski’s personal prestige fell into disrepair.
As a result of the controversial demarcation, Poland was at war with all other neighbors with the exception of Romania and Latvia. The alliance with France of February 19, 1921 made Poland the most important cornerstone in the Cordon sanitaire. However, the task of neutralizing both Soviet Russia and the German Reich had to overtax the forces of Poland, especially since the Weimar Republic failed to achieve a normalization desired by Piłsudski and the German demands for border revision and military equality called the status quo into question. The non-aggression treaties with the USSR (July 25, 1932) and the German Reich (January 26, 1934) were viewed by the partners only as a useful armistice. J. Beck hoped withHitler’s Approval to make Poland the leading power in a “Third Europe” extending from the Baltic to the Adriatic.
The Polish participation in the amputation of Czechoslovakia after the Munich Agreement 1938 (annexation of the Olsa area, October 1938) worsened the political and strategic starting position, especially since Hitler then pushed for a settlement of the Danzig and the Corridor question. The rejection of the so-called global solution (Danzig German, extraterritorial iron and highway through the Polish corridor, Poland’s accession to the Anti-Comintern Pact) on March 26th and the British declaration of guarantee on March 31st, 1939 was taken by Hitler on April 3rd To give orders to prepare for an attack and to terminate the non-aggression agreement on April 28th. A German-Soviet non-aggression treaty signed on August 23 (Hitler-Stalin Pact) provided for the partition of Poland in a secret additional protocol. With the attack on Poland on September 1, 1939, Hitler started World War II.