Castello Estense became property of the Papacy because it was stolen from the Este family. Italy had this rule that if a male heir could not be found then the property went to the wife's family and in this case it happened to be a Pope,which happens to be an unscriptural position in the Lord's Church as is everything else the Catholic church does. Those responsible for this didn't even try to search for another male member of the Este family. You see the Este family had been fighting the Papacy for years for the power to lead Italy. I can say this because I am a decendant of the Este family who were Dukes of several regions in Italy. The title of Duke and the properties taken from them so many years ago should be returned to the Este(Estes)family as soon as possible.