Until the early 19th century, German lands constituted the core part of the highly decentralised
Holy Roman Empire. Each of the
roughly 1,800 individual political entities within the Empire had varying (or non-existent) definitions on who they considered to be members of their polity. "Citizenship" in this context was tied to a person's settlement in a particular municipality and individuals found outside of their ordinary places of residence could be deported to other parts of imperial territory. The
modern concept of citizenship, as a formal and legal relationship between an individual and a
state that confers privileges to holders and a status that persists beyond continued territorial residence, emerged during the
French Revolution. Following the
dissolution of the Holy Roman Empire in 1806, this model of citizenship was imported into the German territories that became part of the French-led
Confederation of the Rhine, though any applicable legislation from this period was repealed in the 1810s shortly after French defeat in the
Napoleonic Wars. Outside of this Confederation,
Austria enacted its first codified regulations based on the modern citizenship concept in 1811. As a result of the
Congress of Vienna, the
German Confederation was created in 1815 as a permanent replacement for the Holy Roman Empire and included virtually all of the former Empire's territory. This political structure was not a
federal state and sovereign power remained with the
38 individual member states. Each state continued to hold jurisdiction over citizenship, but the vast majority of them passed no specific codified laws on the subject until the mid-19th century.
Prussia enacted its first citizenship law in 1842. Other than through naturalisation, Prussian citizenship was only passed by descent from a Prussian father (or mother, if the parents were unmarried).
Confederal policy alignment Any applicable contemporary legislation in the Confederation was inconsistent among the states and generally ineffectual at determining the citizenship of a particular person. State regulations often assumed the existence of some type of citizenship that a child would inherit from their father at the time of their birth. However, any person born in the 18th century who would have been a citizen of an area of the Holy Roman Empire that no longer existed as a political entity would have had an undefined status in state law. Conversely, every state had concluded by the 1820s at least one treaty with some or all other members of the Confederation that detailed the deportation of undesirable persons without state citizenship and process of "implicit
naturalisation". A German who resided in another state for at least 10 years was considered to have been naturalised implicitly in their new place of domicile. An implicitly naturalised father would have automatically passed his changed citizenship status to his entire family. In seven states, this process was extended to any alien who fulfilled the minimum residence requirement. These interstate treaties additionally clarified the position of persons with unclear status, who were granted the contemporary existing citizenship of their birthplace (if that was uncertain, then the place where they were found). Germans lost their state citizenship if they left state territory with the intent to reside elsewhere permanently, had obtained formal permission to emigrate, or otherwise continuously lived outside of their home state for at least 10 years. Theoretically, the
Constitution of the German Confederation created a common German nationality. Article 18 of the document detailed a set of basic rights for every German; any subject of a German state was entitled to freely purchase property in any part of the Confederation, emigrate to other states willing to admit them, enlist in another state's armed forces or civil service, and were exempt from a tax on emigration. In practice, the member states did not permit Germans from other states to freely immigrate into their territories, rendering these constitutional rights generally moot. The
Frankfurt Parliament expanded on this idea of a unified German nationality; any state citizen of the
short-lived 1848–1849 German Empire was also a German national, and all German nationals held the same rights as citizens of any German state. Multilateral negotiations among the states resumed after the German Confederation was reconstituted in 1849. Prussia and 20 other states agreed on the Gotha Treaty in 1851, which lowered the residence requirement for implicit naturalisation to five years and introduced a formal distinction between emigration to other German states and emigration to jurisdictions outside of the Confederation. All German states had acceded to this treaty by 1861.
Unification and imperial law The Confederation was dissolved in 1866 as a consequence of the
Austro-Prussian War. Prussia formed a new union, the
North German Confederation, consisting of all the German states north of the
Main. Four southern states (
Baden,
Bavaria,
Hesse, and
Württemberg) remained independent until their accession to the union during the 1870
Franco-Prussian War. Prussia's 1842 citizenship law served as the basis for federal nationality regulations, which were adopted that same year. The
United States negotiated during this time a set of individual
Bancroft Treaties with the North German Confederation and the four southern states for mutual recognition of each other's naturalised citizens. Following the North German victory against France, the Confederation was reformed into the
German Empire in 1871. International bilateral agreements with the southern German states became superseded by imperial law. In the annexed region of
Alsace–Lorraine, residents were allowed a choice between German and French nationalities. Individuals electing to remain French were required to permanently depart for France by 1 October 1872, although those who did not leave by then were allowed to remain, with German citizenship. Former Confederation members
Liechtenstein (closely aligned with Austria) and
Luxembourg (permanently neutral under the 1867
Treaty of London and in
personal union with the
Netherlands) continued as independent states outside of the German Empire. State citizenship remained principally important in almost all of Germany; imperial citizenship was held by virtue of holding state citizenship, which continued to be acquired in separate processes per state, and German passports listed a holder's nationality as Prussian, Bavarian, Saxon, or whichever label was applicable. However, because Alsatian-Lorrainers and white residents of
German colonies were not domiciled in a federal state, they were simply "German". The concept of a German nationality based on ethnicity and descent became a core principle in the 1913 Imperial and State Citizenship Act (). While prior regulations had maintained preexisting models of state membership through residency, this law made descent from German heritage the primary qualification for nationality. Before the law's enactment on January 1, 1914, Germans who lived abroad for more than 10 years were automatically deprived of their nationality but after this reform, any former national who remained living overseas (as well as any of their descendants) were able to apply for German nationality with no requirement to reestablish residence in Germany. Individuals who became nationals in this way were granted "direct imperial citizenship" rather than citizenship of any particular state. Germans could still be automatically denaturalised after extended residence overseas or obtaining another nationality, but this could be avoided by registering their intent to continue holding German citizenship at a German consulate. Foreigners resident in Germany who held no criminal record, maintained their own housing, and provided for themselves and their families could apply for naturalisation. However, fulfilling the technical requirements did not give applicants the right to become German nationals. Final approval for a grant of nationality was given at the sole discretion of the imperial government, which was extremely restrictive in practice. Only applicants who had served for at least one year in the German military or those who were employed by the German government and had met the other naturalisation requirements were entitled to become German nationals by right. Colonial subjects () held an unclearly defined legal status and were never granted German nationality at large. Any children of mixed-race heritage had to be officially approved for "European" status, subject to detailed examination of an applicant's heritage, education, professional background, and social standing. Any other native resident of a German colony, or foreigners domiciled there, would have been required to naturalise to acquire German nationality. == Interwar and Nazi regulations ==