Prince Edward and Sophie Stand in for King Charles at Historic Parade [Video]

Prince Edward and Sophie, the Duchess of Edinburgh took part in a historic Buckingham Palace ceremony on Monday as King Charles continues his treatment for cancer.

Tourists watching the traditional Changing of the Guard through the railings witnessed the unique treat of watching French troops join their British counterparts in an unprecedented move for the daily ceremony.

King Charles asked his brother Edward, 60, and sister-in-law Sophie, 59, to stand in for him at the special parade in honor of the 120^th anniversary of a key diplomatic agreement between the U.K. and France known as the “entente cordiale.”

Since his cancer diagnosis, which was announced on Feb. 5, King Charles continued to work behind the scenes but has not been able to carry out most of his public duties. On previous occasions, his wife Queen Camilla, 76, …