In our timeline, Charles the Bold, Duke of Burgundy, held Lancastrian sympathies up until the Readeption, when he switched to supporting the Yorks militarily. This was a huge boon for the Yorkists and helped them emerge triumphant against the Lancastrians in the Readeption. But what if Charles’s sympathies for the House of Lancaster not only remained, but he supported them militarily too? Firstly, how does this happen? Maybe Edward IV takes a French bride and/or a pro-French foreign policy? Or maybe, Charles just sees it as more beneficial to him? Maybe Edward of Westminster could get a Burgundian proxy bride? Charles does have a few cousins he could marry (Margaret of Scotland being one of them). Alternatively, Westminster could marry a Burgundian noblewoman. Would Charles supporting the Lancastrians’ cause Louis XI of France to support the Yorkists to prevent a Burgundian friendly King sitting on the English throne? How would this influence the Lancastrians’s moves against the House of York?
Also, in case anyone was wondering, I know Charles chose to marry Margaret of York pre-Readeption, but what I’ve read said he still didn’t fully support the Yorkists and likewise, fully oppose the Lancastrians, until the Readeption.
Also, in case anyone was wondering, I know Charles chose to marry Margaret of York pre-Readeption, but what I’ve read said he still didn’t fully support the Yorkists and likewise, fully oppose the Lancastrians, until the Readeption.