Set in the fictional country of Valaria, the story concerns a royal couple who dislike each other but ultimately fall in love.

It starred Winifred Barnes, José Collins and Arthur Wontner, who played the Ruritanian prince.

The Happy Day opened during World War I in the same year as three other tremendously successful shows in London: Chu Chin Chow, Theodore & Co and The Bing Boys are Here.

Audiences, including servicemen on leave, wanted light and uplifting entertainment during the war, and these shows delivered it.

A review in The Illustrated London News commented that the costumes were "sumptuous" and praised the comedy and the music of the piece, as well as the cast, especially Collins "with her attractive voice and picturesque personality.