Hi Bernard,
I have just finished the Empty Throne. I grew up in Widnes and knew all about Ethefrida, the Lady of Mercia. The reason being that the Runcorn-Widnes Railway Bridge is called the Ethelfrida Bridge. She was always titled a Queen locally though.
When they built the bridge they found remains of Ethelfrida burh there. I believe the actuall built the main supports on the Runcorn side on top of the remains.
Tragic but at the narrowest point, which was the same reason Ethelfrida built there. It protected an easy crossing.
A good history of it can be found here. http://www.runcornhistsoc.org.uk/ethelfleda/menu_of_Ethelfleda_pages.html
Sorry if I am telling you something you already know. I just thought you may find it interesting. I love the book, I really enjoy the Warrior saga.
Please please finish the Starbuck Chronicles. It needs an ending! I need closure!
Kind regards
Alistair