There are some truly stunning pieces of art connected to the George RR Martin novels, the following link being a prime example.

However, there are alternatives? With a few tweaks and a little imagination I have always thought that the art of the Pre-Raphaelites makes for a perfect fit; the next two paintings being a case in point.
House Lannister anybody?

With her auburn hair, the lady could easily be re imagined as a Tully from Riverrun.

Just Google Pre-Raphaelite art for many more examples or visit the dedicated link detailing all things Pre-Raphaelite.
Holy moly. I never thought of the Lannister and Tully comparisons. Genius!