Valisar Trilogy by Fiona McIntosh

Royal Exile: The first instalment of a thrilling new epic fantasy trilogy from the rising star of the genre. Led by Loethar, an ambitious and ruthless tyrant, a terrifying army of mercenaries and renegades from the great southern steppes threaten to overwhelm the Kingdom of Penraven, having already overthrown its two neighbouring realms, leaving a trail of devastation and broken lives in their wake. Penraven is Loethar's most desired prize, not only because of its wealth, safe harbour, extensive coastline, and abundant natural resources. This time the tyrant wants more than a crown. Driven by dreams of empire, fuelled by his increasing obsession with magic, Loethar's plan to overthrow King Brennus of Penraven, 9th of the Valisars, was cemented the hour upon when he learned that Brennus possessed the power of coercion. All of the Valisar heirs have been blessed down the ages with the sinister ability to bend people entirely to their will and Loethar is convinced that if he consumes these empowered people he will then be imbued with their skills and magics! and be unstoppable.

Tyrant's Blood: The second instalment of Fiona McIntosh's gripping epic fantasy, set in a world torn by revenge, love and ancient magic. Ten years have passed since Loethar, the barbarian warlord from the Likurian steppes, devoured the Devona Set with his army of mercenaries, decimating their ruling families and settling in their primary kingdom of Penraven. Believing the Valisar heirs of Penraven to be dead, he has styled himself as emperor and continues his efforts to integrate his people into the native population. But abandoning his more violent methods of persuasion hasn't quelled the undercurrent of rebellion; for the Valisar heirs do live. Hidden from the barbarian's wrath by loyal allies who risk everything for the future of their kingdom, they are bound to return and seek a tyrant's blood for the havoc he has wreaked.

King's Wrath: The thrilling conclusion to the breathtaking saga of power, blood, birthright, and enchantment.
The barbarian King Loethar may have gained his throne through brutality and bloodshed, but he has ruled Penraven with unexpected wisdom. Now his innumerable past sins threaten his reign - as Valisars who escaped slaughter prepare to rise up. Loyalties shift and new alliances are formed as the truth of history begins to emerge.
King-in-exile Leonel hungers for revenge against the man he considers the usurper of his throne. Yet Leo is unaware of another who wields the enchantment he covets - the once-charming "halfwit" brother Piven, now a powerful youth whose exceptional cunning is matched only by his ruthless desire for the throne.
But the efforts of all three to hold or gain control of Penraven may well be in vain, for the true inheritor of the Valisar Legacy is being called home . . . to claim her crown.