Why is the wife of a duke called a duchess and not a dukess?

[plowter]

Why is the wife of a duke called a duchess and not a dukess?

[nungate]

The Marchioness of Tavistock was registering to stay in a New York Hotel and when the Receptionist saw her title she asked her "Is the Martian coming to stay too?"

[Quizmonster]

In Glasgow, the Queen's consort used to be referred to as ra Chooky Embra, I believe.

[THECORBYLOON]

Is he not still, QM?

[thenry]

You need to watch the film 'Unforgiven' ! Gene Hackman 'and the duck says' (English Bob) 'The Duke !' (Gene again) 'The Duck I says !'

[jno]

I don't know why he says Duck, Hollywood had no problems calling John Wayne the Dook, did they?