On June 10, 1688, James Francis Edward Stuart (to his supporters James III, to his detractors the "Old Pretender") was born to James II and his second wife, Mary of Modena. According to English law, a son would take precedence over an older daughter in the succession of the throne. Those who looked forward to James II's death so that his daughter Mary, who was married to William of Orange, would succeed to the throne, had their hopes shattered. Seven men wrote a letter to William, asking him to invade England for the throne.William was more than happy to oblige, and landed in England. Mary of Modena and her son fled to France, and James II followed shortly.
Now there were two opposing camps in England. The Williamites believed that William III had a right to sit on the throne. The Jacobites believed that William III was a usurper, and continued to pledge allegiance to James II, and when he died, to James III. The Jacobites remained a force to be reckoned with in European politics for nearly a century.
The white rose or white cockade was a symbol of Jacobitism. To symbolize their unity with France, James II's army wore white cockades (Williamites wore green plants or orange clothing), and the symbolism of the white rose/cockade carried over for centuries to the present day.
Happy White Rose Day!