"In the summer of nineteen-thirty-five the whole school was forced to wear rosettes of red, white and blue ribbons in the lapels of its blazers, because of the Silver Jubilee."
King George V and Queen Mary in 1927
Public DomainKing George V and Queen Mary in 1927 - Credit: unknown

The Silver Jubilee referred to is that of King George V and his consort, Queen Mary.

George V was King of the United Kingdom and the British Dominions and Emperor of India between 1910 and his death in 1936.

In 1893 he married Princess Victoria Mary of Teck (often known as Princess May of Teck); the couple had five sons and a daughter.

 

Silver Jubilee stamp 1935
Creative Commons AttributionSilver Jubilee stamp 1935 - Credit: Smabs Sputzer, Flickr