Norwegian nationality law is based on the principle of jus sanguinis. In general, Norwegian citizenship is conferred by birth to a Norwegian parent, or by naturalisation in Norway. Birth in Norway In general, birth in Norway does not, in itself, confer Norwegian citizenship as its law uses jus sanguinis policy. Exceptions are made for stateless people and foundlings. Descent from a Norwegian parent Regardless of the place of birth, a child acquires Norwegian citizenship at birth if either parent is a Norwegian citizen. Originally, citizenship was only passed on to the children of Norwegian mothers, as they were the only provable parents, but over time a presumption of paternal parentage created citizenship for the child, and eventually even excluded the maternal jus sanguinis. In more recent times, as of 1 January 1979, mothers' rights to automatically pass on their Norwegian citizenship has been reestablished. The requirement that the mother and father be married to one another was abolished on 1 September 2006. Naturalisation as a Norwegian citizen Generally, it is possible to naturalise as a Norwegian citizen after residing in Norway eight years over the last eleven years, if the applicant qualifies for permanent residence and does not have a criminal record. Exceptions: Applicants with a criminal record must wait a further "quarantine" period dependent on the crime committed before being granted citizenship. Citizens of other Nordic Council countries may naturalise after only a two-year residence. The spouses and non-married cohabitant partners of Norwegian citizens may naturalise as quickly as four years. The requirement is that they have resided in Norway at least three years of the last ten and that the number of years resident and the number of years married, taken together cumulatively, equals at least seven. The children (under the age of 18 years) of citizens of other Nordic Council countries may automatically receive naturalisation with their parents. The children of citizens naturalised from other countries may themselves receive citizenship if they have resided in Norway for the last two years. Former Norwegian citizens may naturalise after one year's residence during the last two years. From 1 September 2008 an applicant for Norwegian citizenship must also give evidence of proficiency in either Norwegian or a Sami language, or give proof of having attended classes in Norwegian for 300 hours, or meet the language requirements for university studies in Norway (i.e., demonstrate proficiency in one of the Scandinavian