Suggest me a dark, ruthless political fantasy book/series

I’m looking for a book that emphasizes the political tensions of its world, with a cast of merciless, power-hungry characters. Something with shifting alliances/backstabbing/revenge, fights over scarce resources, and unjust class systems. The grimmer, the better. Doesn’t have to be fantasy, but something with epic battles, betrayals, and violence. Even better if espionage is a major part of the plot. Thanks!