Hallo, Thomas,
since 19th Century - starting with the French in about 1840 - we got so-called "Kataster-Aemter" recording land surveys both on maps and in books. They didn't really care who the owner was but more how big the property was.
The so-called "Grundbuchamt" (amt always for office) records the owner and the change of owners through the times.
But each deed, each act on property had to be stated by the public notary. And his files are kept in the State Archives because the notaries were called to duty by the State Governments.
Roland