Origin of the Koberstein name!

Finally

The origination of our Koberstein name has been found:

The castle Koberstein was built between 1343 and 1358 by Knight Johann von Kobern, who later called himself after his castle Johann von Koberstein. https://de.wikipedia.org/wiki/Burg_Koberstein

This web page gives more details from the book  about the Koberstein Castle in Altenkirchen. This is part of a two volume book entitled "Chronik Obererbach"
http://terrykoberstein.com/johann1359.htm