House Harkonnen by Brian Herbert

A prequel that traces the brutal ascent and moral decay of a ruthless noble family, following scheming patriarchs and violent heirs as they use betrayal, political maneuvering, and military force to expand their influence within the Imperium; it reveals the origins of the bitter rivalry with the rival house and the events that set the stage for the later struggle over the spice-rich desert world, mixing intimate family drama with grand imperial intrigue.

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