[Catlady]

Originally Posted by gmw

Spoiler:

Elizabeth of York (Elizabeth Woodville's daughter) is seen to fall in love with Richard III and the two plan to marry (apparently there really were rumours to this effect at the time), and at the same time Henry Tudor is declaring he will marry her when he takes the throne - as agreed in private between Elizabeth Woodville and Margaret Beaufort. (I guess royalty and incest go together to some extent, but Richard and his niece? Can the niece really overlook Richard usurping the crown from her brother? I'm having some trouble with that ... but "the past is a foreign country, they do things differently there" - thank you, L.P. Hartley.)

I don't think the information about Elizabeth of York is particularly spoilery, but I'll follow your lead:

Spoiler:

Weir devotes a chapter to Elizabeth's liaison with Richard III.

By the end of 1484 it was clear that Queen Anne was a sick woman, unlikely to have any more children, and probably not long for this world. Elizabeth Wydville, following her usual pragmatic instincts, and having now abandoned her hopes of Henry Tudor, saw some advantage for her daughter and herself in this situation, for if Anne died, as seemed likely, the King would be expected to marry again in the hope of providing for the succession. In such circumstances, who better to mate with him than the Lady Elizabeth, regarded by many as the rightful heiress of the House of York? Marriage to her would place Richard III in an unassailable position: as husband of the woman many people regarded as the lawful Queen of England he would enjoy the unchallenged right to wear the crown. Elizabeth would be accorded her rightful rank and dignity and, even more to the point, Elizabeth Wydville could expect to be restored to power and influence as the mother of the Queen Regnant.

Weir says the relationship between Richard and Lady Elizabeth was both pragmatic and passionate. She also says:

The King’s determination to marry his niece is virtual proof, if any were needed, that the precontract story on which his title was based was pure invention. Had it been true, Richard would not now have been contemplating the marriage to strengthen his position. His pursuit of Elizabeth was not only a tacit acknowledgement of the widespread recognition of her as the rightful queen, but also amounted to confirmation that the Princes were dead. Marriage to her would crush Henry Tudor’s pretensions once and for all, and it would hopefully silence the ever-present rumours about her brothers. It would stabilise Richard’s tenure of the throne, enlist the Wydvilles on the side of the Crown, and in every way make sound political sense.

The fact that she [Elizabeth of York] could contemplate such a marriage shows her to have been as much of a pragmatist as her mother and confirms that her ambition to wear a crown was greater than her grief for brothers who might never have been close to her.

When the marriage to Richard didn't happen, Elizabeth turned against him and back to Henry Tudor, and finally got the crown she wanted.