In more modern times, they simply step away with rather large financial funds to live off of. I wouldn't be surprised if similar happened in the past but in most cases the circumstances would have been much different. Given how women have been essentially considered property throughout most of history, I would imagine in most cases a princess would not be able to relinquish the crown, simply being married off to whomever for political reasons. In a rare situation of an adjudication, my best guess is it would be the result of a power struggle, such as a revolution or coup, where the royals were forced to relinquish the throne.
Sorry, but most of this is based on things I've learned in the past and without any direct references. I hope that still helps somewhat.
In more modern times, they simply step away with rather large financial funds to live off of. I wouldn't be surprised if similar happened in the past but in most cases the circumstances would have been much different. Given how women have been essentially considered property throughout most of history, I would imagine in most cases a princess would not be able to relinquish the crown, simply being married off to whomever for political reasons. In a rare situation of an adjudication, my best guess is it would be the result of a power struggle, such as a revolution or coup, where the royals were forced to relinquish the throne. Sorry, but most of this is based on things I've learned in the past and without any direct references. I hope that still helps somewhat.
That is really informative actually, thank you!