That said, the writers of these screenplays did beat the odds though, or the prejudice if you will, against historical pieces. Producers are the people who find the money to actually shoot the movie of your screenplay. And good producers are smart, film savvy and TIGHT; that's how you get bankrolled to shoot another film... paying attention to the bottom line.
The reason that period pieces or historical films put feat into the hearts of most producers is you can't just walk out the door and start shooting. You have to have period specific costumes (ka-ching) and all kinds of specialty coaching for your actors (sword play, accents, horse riding (ka-ching, ka-ching, ka-ching). And all of this happens BEFORE you ever shoot a foot of film. Little wonder the mere mention of a historical script sends most producers screaming from the room.
But back to the opening paragraph and those fantastic period piece films which all won rave reviews too - I might add. The one thing they all had in common was FANTASTIC scripts. Fantastic scripts make believers out of top tier actors, who are craving a part to really challenge them . And top tier actors make believers out of tight-fisted producers and distributors.
So my advice to you, and any writer, is to ALWAYS write what you LOVE. Write your period piece screenplay to the absolute best of your ability. Create a main character that every actress on the planet would kill to play. Create a storyline and theme that is TIMELESS, and your audience won't give hoot that your lead actor is wearing a codpiece!
I hope this helps. And I do wish you luck with your screenplay - and let me know when you've completed your script. I'd love to read your work!