The Plantagenets, specifically the House of York. I get that the Tudors descend from the Yorks via Elizabeth of York, but I've always been obsessed with what might have happened if Richard III had defeated Henry Tudor at Bosworth and what might have come after. Would he have married Elizabeth of York to combine the two lines - not so out of the realm of possibility if one considers the Habsburgs and their tradition of uncles marrying their nieces. It would likely have had a similar result that the York-Tudor marriage had - if you supported Edward IV's children over Richard, Elizabeth of York would have been Queen and would have passed her claim on to her sons, if you supported Richard then the rightful King was on his throne and had survived two deadly rebellions against him. By the time the next generation came along, things would have largely been smoothed out (though I imagine there would be some exceptions - would the de la Poles have caused trouble? etc). Or, alternatively, would Richard have sought international recognition through a foreign bride and perhaps kept his nieces close, perhaps pushing them into convents to prevent that bloodline from propagating?
