I am ineligible for any prizes but my favourite female character is Katherine de Roet, later Swynford, the long-time lover and later wife, of John of Gaunt.
When they married she became Duchess of Lancaster.
I mentioned her on another thread and someone very kindly sent me a link to an audio book of 'Katherine' about her life. It's a fascinating read.
This classic was written by Anya Seton and is far from being a dusty ol' history book.
It's a vibrant and interesting story about a very strong and clever woman.
Thanks to Littleflo, who sent the link in March this year, I was able to persuade my local library to buy it and it's just come up on my borrower's list. I shall be enjoying re-reading it this weekend.