William was a member of the House of Trangau, who had possessions in Salzburggau, Isengau and Sundergau, and is considered the founder of the noble Bavarian...

Berchtesgadener Land. Since the early Middle Ages, the area was part of the Salzburggau within the Bavarian stem duchy. Already about 700 Duke Theodo of Bavaria...

and the lower Rott in Lower Bavaria and Upper Austria, south of Passau Salzburggau [de]: along the middle Salzach in Salzburg, around Salzburg (city) Schweinachgau:...