Portugal is one of the few countries in Europe that makes acquiring citizenship somewhat easy…
Anyone with five years of official residency is entitled to apply for Portuguese citizenship. You must also prove “sufficient knowledge” of Portuguese, as well as “effective links to the national community.”
Those with Portuguese grandparents can skip the residency requirement when being naturalized.
Portugal recognizes jus sanguinis as well as jus soli in certain circumstances. Parents must have been legally resident in the country for five years in order to seek citizenship for their children born in the country; children born in Portugal to parents on tourist or short-stay visas are ineligible to seek citizenship.
Children born to Portuguese parents overseas must be registered with the country or declare their desire to obtain citizenship in order to gain it.
Children and grandchildren of Portuguese citizens that have their birth registered with the civil registry and indicate they want to be recognized as citizens are accepted under this liberal arrangement.
Individuals from the former Portuguese colonies of Macau, East Timor, and Portuguese India (Goa, Damão, Diu, Nagar Haveli) can apply for citizenship, too.
Even more recently, Portugal began granting citizenship to persons of Sephardic Jewish ancestry who had been expelled during the inquisitions; applicants may be approved regardless of their current religious status as long as they can establish their family history in the region.