Schutzjude
Schutzjude (German for "Protected Jew") was a status for German Jews granted by the imperial, princely or royal courts.
Within the Holy Roman Empire, except of some eastern territories gained to the Empire in the 11th and 12th c. (e.g. Brandenburg), Jews usually had the status as Servi camerae regis. This status included imperial protection and the levying of special taxes from the Jews in favour of the Empire's treasury (Latin: camera regis). But the emperors, always short in money, alienated - by sale or pledge - their privilege to levy extra taxes from Jews, not all at once, but territory by territory to different creditors and purchasers. Thus Jews lost their - anyway not always reliable - imperial protection.
Many territories, who gained supremacy over the Jews living within their boundaries, expelled them. After the general expulsions of the Jews from a territory often only single Jews - if at all any - were granted the personal - sometimes inheritable by only one son, rarely by by all sons, sometimes uninheritable - privilege (usually called Geleitsbrief, Schutzbrief, in Brandenburg the pertaining deed issued used to be called Patent) - to reside within a territory. Jews holding a Schutzbrief (writ of protection), Geleitbrief (writ of escort) or Patent were thus called Schutzjude, vergeleiteter Jude or Patentjude as opposed to Jews (unvergeleitete Juden), who had no right of residence. Unvergeleitete Juden were not allowed to marry, thus they spent their life either unmarried as a member of the household of a privileged relative or employer, holding a privilege.
For example, in October 1763 the King Frederick II of Brandenburg-Prussia granted Moses Mendelssohn, until then a merely tolerated Jew under daily threat of expulsion, a personal, uninheritable privilege, which assured his right to undisturbed residence in Berlin. His wife and children, who had no independent permission to reside, lost their status of family member of a Schutzjude when Mendelssohn died in 1786. They were later granted inheritable Patents. In 1810 Stein's Prussian Reforms introduced a freely inheritable Prussian citizenship for all subjects of the king, doing away with the different prior legal status of the Estates, such as the Nobility, the burghers of chartered the cities, the unfree peasants, the officialdom at the court, the Patent-Jews, and the Huguenots.