Is There A Gap In The Costume Drama Market?

With the hype of Downton Abbey now partially eclipsed by the disappointment in Julian Fellowes' Titanic, some commentators are asking have audiences now had their fill of the historic costume drama formula?

Well here at History and the Sock Merchant I'd like to throw in to the mix another theory, perhaps audiences are tired of costume dramas which focus on the same old periods in History.
Essentially it seem there are two kinds of costume drama in the world today. Those that are based on books and therefore the bias of time period is related to when the book is written or set, or made for TV period dramas often with the American market in mind (though often underestimating the American audience) which will often feature well known historical characters or periods and, it must be said, frequently dissolve into a caricature or blatant sex fest.

With this in mind are there gaps in period drama periods? Is there any time in history that you feel is underrepresented in the costume drama market or alternatively are you one of a growing number who are discontented with the way history is portrayed by the filmmakers? Tweet/Feedback me your thoughts on what periods in history you'd like to see dramatised and perhaps together we can usher in a new kind of costume drama.