George Grossmith was indeed a man of parts; as well as co-writing The Diary Of A Nobody with his brother Weedon (originally a Punch series but later published as a book in revised form {if interested, see my entry on the Grossmiths in the Continuum Encyclopedia of British Literature and on 'The Diary' in The Cambridge Guide to Literature in English}), he also originated the performances, under Gilbert's own direction, of the main comic male characters {The Mikado, Sir Joseph Porter, Major-General Stanley, the Lord Chancellor, Jack Point &c} in the G&S operas. The productions by the D'Oyly Carte company, who had the monopoly of the performances by copyright for 50 years after Gilbert's death, always repeated his 'business' faithfully, word for word & gesture for gesture. I remember when they came out of copyright, there were many who campaigned for the copyright to be permanently extended by Act of Parliament, lest some director or actor might ever vary the sacred characterisations and productions!

Whether he or his son [called 'Grossmith Jnr' above, note] was the author of 'Bertie' I am not sure.

~M~