after retiring from london to live in lavish state at greenwich, margaret was occupied with the care of her young son and did not display any signs of political will until she believed her husband was threatened with deposition by the ambitious richard of york, 3rd duke of york, who, to her consternation, had been appointed lord protector while henry was mentally incapacitated from 1453 to 1454. the duke was a credible claimant to the english throne and by the end of his protectorship there were many powerful nobles and relatives prepared to back his claim. the duke of york was powerful; henry's advisers corrupt; henry himself trusting, pliable, and increasingly unstable; margaret defiantly unpopular, grimly and gallantly determined to maintain the english crown for her progeny. yet at least one scholar identifies the source of the eventual lancastrian downfall not as york's ambitions nearly so much as margaret's ill-judged enmity toward york and her over-indulgence in unpopular allies. nevertheless, queen margaret was a powerful force in the world of politics. king henry was putty in her hands when she wanted something done.