An anonymous Yorkist supporter wrote an account describing Edward IV’s march through England in the spring of 1471, when he came to reclaim his throne from the Lancastrian Henry VI.
On 7th April, Palm Sunday, Edward heard mass in the parish church at Daventry, and during the service a miracle occurred, witnessed by everyone present. At that time it was the rule to ‘shut, close and cover’ all images in churches, from Ash Wednesday to the morning of Easter Sunday, and this had indeed been done at Daventry. Imagine the shock when suddenly there was a loud crack from the covering around an image of St Anne, Mother of Mary, and the shutters opened a little, before closing again. No human hand had touched the covering, nor did it when the shutters were flung open again, and remained open, the image inside exposed to all eyes. All present fell to their knees.
King Edward, throughout his exile, had prayed for help to to God, Our Lady, St George…and especially to St Anne. As may be imagined, he took this event as a miracle, and a sign that his bid to retrieve his throne had support on high. He could not fail in his quest to rule England again. Not long afterwards he won the decisive Battle of Barnet.
Needless to say, the Lancastrian accounts of Edward’s return do not mention the miracle, but to the Yorkists the saint’s intervention pointed to Edward as the rightful successor to Richard II’s line. Specifically through Philippa of Clarence, who was desended from a senior Plantagenet line to that of the Lancastrians. Edward was therefore a member of the de jure lineage of kings, unlike that of the Lancastrian monarchs who were kings de facto but not de jure because of Henry IV’s intrusion and usurpation. St Anne had shown her favour to the Yorkist claim. Word of the miracle was soon spreading, aided no doubt by a little subtle assistance from Edward’s supporters.
If you wish to read more detail and explanation of the Yorkist resort to female sanctity and symbolism upon which to base their claim to the throne, see:-
“Spiritual Economies: Female Monasticism in Later Medieval England” by Nancy Bradley Warren.