NOT Prince William, but THIS member of the Royal Family fills in for King Charles; Why?

During King Charles' recent trip to Italy, Sophie, Duchess of Edinburgh, represented the monarch at the Sovereign's Parade, Sandhurst Royal Military Academy. This occurred as Prince William and Princess Kate are spending time with their family during school break, following Kate's cancer diagnosis. The parade also marked a historic moment for Sandhurst, featuring its first all-female Banner Party.

NOT Prince William, but THIS member of the Royal Family fills in for King Charles; Why?
During King Charles' recent trip to Italy, Sophie, Duchess of Edinburgh, represented the monarch at the Sovereign's Parade, Sandhurst Royal Military Academy. This occurred as Prince William and Princess Kate are spending time with their family during school break, following Kate's cancer diagnosis. The parade also marked a historic moment for Sandhurst, featuring its first all-female Banner Party.