Population from the former Kingdom of Poland
In order to obtain Polish citizenship after the Second Republic of Poland regained its independence, the population living in the areas of the former Kingdom of Poland had to prove that they had settled on this territory of the former Russian Empire, which was granted to Poland after World War I and the Polish-Soviet War of 1920. Settlement, however, should not be understood as actual, even long-term residence in a given territory, but as a kind of public-law bond connecting an individual with a given territory.
The prerequisites for acquiring Polish citizenship ex lege by persons coming from the area of the former Kingdom of Poland were set out in Article 2 point 1a of the Act of 1920 on Citizenship of the Polish State. In order to acquire Polish citizenship from the moment the Act came into force, one had to be settled on the territory of the Polish State and have no foreign citizenship. Anyone who was enrolled, or at the time of the Kingdom's existence had the right to be enrolled, in the permanent population registers of the Kingdom of Poland was considered to be settled within the meaning of the said Act, i.e. to be a Polish citizen by operation of law. This "settlement" had to be proved as at the date of promulgation of the aforementioned Act, i.e. 31 January 1920. The acquisition of citizenship under the provisions of this Act was therefore not conditional on actual residence on Polish territory.
The question of enrolment in the permanent population registers in the Kingdom of Poland had to be assessed according to the provisions in force at the time of its existence. On the legal side, the matter of keeping permanent population registers in the Kingdom of Poland was regulated by:
- Instruction on Maintaining and Maintaining Population Books in Towns and Rural Municipalities of the Kingdom of Poland approved by the decision of the Administrative Council of 10/22 November 1861
- Instruction on Maintaining and Maintaining Population Registers for the Capital City of Warsaw approved by a decision of the Administrative Council on 11/23 February 1866
- the Ukaz of 8 July 1868 on the mode of resettlement from the Russian Empire to the Kingdom of Poland introduced minor changes to the two instructions above.