Although the first documentary mention in itself does not establish the time of Pfalzfeld's birth, another document does narrow down that time somewhat. An 820 donation document from King Louis the Pious to the Sankt Goar Monastery included a great forested area west of the Rhine stretching to the Baybach. Mentioned in this document is Biebernheim, nowadays an outlying centre of Sankt Goar, but nowhere does it mention Pfalzfeld. By no means did donation documents always mention every small village involved in the transfers of property, but if a little place like Biebernheim was mentioned, then surely Pfalzfeld, too, would have been mentioned, had it then existed. This leads to the conclusion that Pfalzfeld must have been founded sometime between the dates of these two documents, 820 and 893, as a newly cleared patch of the forest.