Saxony Naturalization and Citizenship
A Stadtbuch is a record a city kept, starting in medieval times. It is a collection of written pages, first in Latin later in the vernacular of the area.
The content of a Stadtbuch varies with growing literacy. The oldest records contain a mixed variety (Stadtbuch mit vermischtem Inhalt), such as laying down the law for the city, collecting judgments. Legal certainty was created and citizens received parameters by which to interact with the city administration, legal issues, business affairs etc. For instance, land records were created by town clerks and stored by authority of the city council. Such records then received public credibility and became evidential. Since the 14th century city records became more categorized. The matters of the city council were kept separate from business between citizens, such as property issues and marriage contracts. There was a book for financial matters, statutes, city law and ordinances as well as for judicial protocols, in and outgoing correspondence, citizenship records and expatriations.
A Stadtbuch allows a glimpse into the life of citizenry and touches on the development of city law, politics, social structure and population statistics.
It has become the project of a group of people to evaluate and establish an inventory of Stadtbücher from the beginning to 1800 for the states of Mecklenburg-Vorpommern, Brandenburg, Berlin, Sachsen-Anhalt, Thuringia and Saxony. A list of Stadtbücher that already have been evaluated can be looked at here. The list basically explains which records are available for a given town. The documentation is a work in progress. More can be read about it here.
In Germany as well as in the Kingdom of Saxony, authorities kept the so called Bürgerbücher or Bürgerrollen (lists of people who lived in cities, who had been given the right to live in a city (Neubürger) because they paid a sum of money for the privilege ( the sum was lower when a new citizen married a girl or a widow from a particular city). They now had the privilege to practise a profession, they had voting rights, but they also had to pay taxes and defend the city. Well into the 19th century such books are a well-documented source in which one can find where the new citizens originated from. Bürgerbücher are the invention of cities, therefore, one can find such documents only in cities. When cities did not publish Bürgerbücher one may find information about new citizens in their yearly accounting books (Stadtrechnungen or Ratsprotokolle). Often Bürgerbücher were published. A search in KVK is recommended.
This is a databak which will give titles of Bürgerbücher and where such titles can be found.
Source: GenWiki Bürgerbuch
The Family History Library also has Bürgerbücher which can be searched under Keyword search. Enter: Bürgerbücher