While Mary was still mourning the death of her husband, the English queen of the House of Lancaster, Margaret of Anjou, fled north across the border seeking refuge from the Yorkists. Mary sympathetically aided Margaret and took Edward of Westminster into her household to keep them out of Yorkist hands. Mary's dealings with Margaret were mainly to provide aid to the deposed queen. Mary gave a number of Scottish troops to help Margaret and the Lancastrian cause. Mary and Margaret also organised a betrothal between Margaret's son, Edward, and Mary's daughter Margaret in 1461. In return for her support, Mary asked for the town of Berwick on the Anglo-Scottish border, which Margaret was willing to give up. Relations between the two women deteriorated, however, with the increasingly friendly alliance between King Edward IV of England and Duke Philip of Burgundy. Any support by Mary for Margaret, Edward IV's enemy, threatened the alliance that Philip wanted with Edward IV against King Louis XI of France.