The applicant was born in the US, and his birth certificate indicated a Polish national as the father, and an unknown surrogate mother as the mother. Polish authorities refused to confirm the applicant acquired Polish nationality at birth as a child of a Polish parent, because the birth certificate is against the Polish public order, in particular the prohibition of surrogacy. The courts ruled in favour of the applicant, stating that confirmation of his Polish nationality on the basis of the birth certificate does not amount to validation of surrogacy.
The applicant acquired Austrian nationality in 1995 and renounced her former Turkish nationality in 1996 as a condition for retaining the Austrian nationality. In 2018 the Austrian authorities declared that she has no longer been an Austrian national since 1997 as it appeared that she voluntarily re-acquired her Turkish nationality at that time, which is a ground for automatic loss of Austrian nationality. The Court set aside the determination of loss of Austrian nationality as it did not carry out a proportionality test on the basis of the Tjebbes judgment.
The applicant naturalised in the Netherlands in 2003, but the naturalisation was withdrawn in 2013 when the authorities found out she had a criminal conviction in Belgium in 2000 that she failed to mention in her naturalisation application. The applicant argued that the decision depriving her of her Dutch nationality is disproportionate, among others in light of EU law and Rottmann judgment, in particular due to her becoming stateless as a result, and the difficulties she may face re-acquiring her original Ghanaian nationality. The Court rejected the appeal and upheld the decision denaturalising the applicant.
The applicant naturalised in the Netherlands, after having derived his legal residence from being a partner of a Dutch resident. His naturalisation was later withdrawn, as it appeared he has concluded a marriage and fathered a child with another person in Egypt while still deriving residence rights from his relationship in the Netherlands. The Court confirmed the legality of withdrawal, despite the applicant becoming stateless as a result.
The applicant was born in Poland to a Vietnamese mother. When she was 9 years old a Polish citizen formally recognised her as his daughter, and the local authority subsequently confirmed that she is a Polish citizen by birth. She was growing up as a Polish citizen until another 8 years later the central government authorities invalidated the confirmation of nationality by the local authority, as according to the Polish Citizenship Law changes in parenthood can only lead to acquisition of Polish citizenship if they take place within 1 year of birth. The applicant's arguments related to article 8 ECHR, best interests of the child, as well as long-term presumption of Polish citizenship due to no fault of the applicant, although the court dismissed all arguments.