After the death of Edward IV, Richard, Duke of Gloucester was made the regent for the young Edward V. Elizabeth Woodville wasn’t completely happy with the decision and started to fear for her life and that of her children’s when Richard took Edward V to The Tower of London and had Anthony Woodville and Richard Grey—Elizabeth Woodville’s brother and son—executed. She took her children to sanctuary once again.
Within two months, Elizabeth of York was declared illegitimate. Richard stated that his brother had had various secret marriages before Elizabeth Woodville, and knew that at least one of them was true. Therefore, the marriage to Elizabeth was never valid. Edward V could not be crowned king and it would mean Richard would become King of England. Just before this, he had convinced Elizabeth Woodville to let her youngest son, Richard, Duke of Shrewsbury, to join Edward V in The Tower of London. The two boys mysteriously vanished, presumed death.
Whether Elizabeth Woodville knew that her sons were dead or had any idea who caused it is unclear, but she worked on protecting her surviving daughters.
There was on card she could play: put Henry Tudor, son of Margaret Beaufort, on the throne. Even though his came from an illegitimate line, he did come from royal blood and he was the Lancastrian House’s only hope. But she wanted something in return; she wanted her daughter to become Queen Consort of England. Elizabeth and Margaret conspired together to ensure Henry Tudor would kill Richard III and then marry Elizabeth of York.