Jus Sanguinis

Jus sanguinis (Latin: right of blood) is a principle of nationality law by which citizenship is not determined by place of birth but by having one or both parents who are citizens of the nation. It contrasts with jus soli (Latin for "right of soil").

At the end of the 19th century, the French-German debate on nationality saw the French, such as Ernest Renan, oppose the German conception, exemplified by Johann Fichte, who believed in an "objective nationality", based on blood, race or language. Renan's republican conception explains France's early adoption of jus soli. Many nations have a mixture of jus sanguinis and jus soli, including the United States, Canada, Israel, Germany (as of recently), Greece, and Ireland.

Apart from France, jus sanguinis is still the most common means of passing on citizenship in many continental European countries. Some countries provide almost the same rights as a citizen to people born in the country, without actually giving them citizenship. An example is Indfødsret in Denmark, which provides that upon reaching 18, non-citizen residents can decide to take a test to gain citizenship.

Unlike France, some European states (in their modern forms) are postempire creations within the past century. States arising out of the Austro-Hungarian Empire and the Ottoman Empire had huge numbers of ethnic populations outside of their new boundaries, as do most of the former Soviet states. Several had long-standing diasporas that did not conform to 20th century European nationalism and state creation.

In many cases, jus sanguinis rights were mandated by international treaty, with citizenship definitions imposed by the international community. In other cases, minorities were subject to legal and extra-legal persecution and their only option was immigration to their ancestral home country. States offering jus sanguinis rights to ethnic citizens and their descendants include Italy, Greece, Turkey, Bulgaria, and Romania. Each is required by international treaty to extend those rights.