information:classification, linguistic:voice_change, stylistic:tone, information:filtering
Restored Poland (1918–1939)

Despite its large population and economic output, Łódź did not serve as the seat of its province until the 20th century. Following the establishment of the Second Polish Republic, it became the capital of the Łódź Voivodeship in 1919. The early interwar period was characterised by considerable economic hardship and industrial stagnation. The Great Depression and the German–Polish customs war closed western markets to Polish textiles while the Bolshevik Revolution and the Civil War in Russia put an end to the most profitable trade with the East.

Because of rapid and, consequently, chaotic development in the previous century, Łódź did not possess the adequate infrastructure and living standards for its inhabitants. Pollution was acute, sanitary conditions were poor and the authorities did not invest in a sewage treatment system until the 1920s. From 1918 to 1939, many cultural, educational and scientific institutions were created, including elementary schools, museums, art galleries and public libraries which prior to the First World War did not exist. Łódź also began developing an entertainment scene, with 34 movie theatres opened by 1939. On 13 September 1925, the city's first airport, Lublinek, commenced operations. In 1930, the first radio transmission from a newly-founded broadcasting station took place.

The ideological orientation of Łódź was strongly left-wing and the city was a notable centre of socialist, communist and bundist activity in Polish politics during the interbellum.