I recently bought John Peacock's The Chronicle of Western Costume. It's a book I've used many times before via the library, but it was time to just buy it. This doll is an interpretation of one of the outfits on one of the Byzantine pages. There were a few princesses and empresses named Irene (one is even a saint), so that's the name I went with.
As an added bonus, here are the gemstone brushes that I used to make this. You can download the Illustrator zip file here.