Wedding and illegitimate children
Whether a child is married or illegitimate matters to the question of citizenship.
In the period from January 31, 1920 to January 18, 1951, the rule was that wedding children acquired citizenship from their father, and illegitimate children from their mother. Moreover, wedding children lost Polish citizenship along with their father, but illegitimate children did NOT lose Polish citizenship with their mother.
However, illegitimate children could acquire Polish citizenship after their father through recognition, adoption or entitlement. Recognition meant that a man recognized a child as his own, adoption meant adoption, and the right that the mother of an illegitimate child entered into a marriage with the child's father.
Interestingly, the law on Polish citizenship recognized only children up to the age of 18 as children. Meanwhile, until the end of 1945, turning 18 did not mean reaching the age of majority (this is the case only from January 1, 1946, when the Personal Law entered into force). Previously, various regulations were in force in Poland from the period of the partitions. For example, in accordance with Art. 345 of the Civil Code of the Kingdom of Poland, adulthood was not reached until the age of 21. The Universal Book of Civil Laws (ALLGEMEINES BÜRGERLICHES GESETZBUCH) in the territory of the Austrian partition referred to 24 years (§ 21). THE CIVIL CODE in force in the Western Territories of the Republic of Poland (BÜRGERLICHES GESETZBUCH) has ended the age of majority for 21 years. The provisions of the Law of the Russian Empire, which were in force in the Eastern Territories, were similar. Although minors who reached 17 years of age already obtained individual rights characteristic of adults, they reached the age of majority at the age of 21 (§ 213).
In the period from January 19, 1951 to August 21, 1962, the question of the child's origin ceased to be relevant. However, from August 22, 1962, a restrictive regulation was introduced, according to which children born out of wedlock acquire Polish citizenship only on the condition that their recognition takes place within one year of their birth (unless paternity is established by a court of law).