The duchy of Geldern/Guelders/Gelderland OTL passed to the Habsburgs through the Burgundian inheritance, since a duke of Guelders had mortgaged his lands to Philippe le Bon or Charles le Téméraire (can't remember which). When the duke of Guelders died, his son claimed the duchy back from the Burgundians. HOwever, he died, leaving two underage children, twins, Karl II and Philippine. Philippine later married the duke of Lorraine while Karl a Welf princess. Karl later died without legitimate kids, despite the fact that he had warred against the emperor concerning his duchy. However, he left at least four bastards (three of which were boys). So, here's my question, what would happen if Karl II were to have a legitimate son by his wife, Elisabeth of Brunswick? Or even a daughter? How would either situation affect the future of the duchy (obviously the girl would be an heiress to marry for anyone going against the Imperial camp (although I think the duke of Jülich-Kleve-Berg had the next best claim to Guelders in lieu of an heir))? And how legal was the imperial/Burgundian holding of the duchy of Guelders (a case of might makes right? Or simply an expired lease that no-one bothered renewing?).