Kalogridis has done a spectacular job melding history with astrology in the marriage of Catherine de Medici to Henri, Duke d’ Orleans, later king of France (Henry II). Buffeted by traumatic events from a young age in the Medici court in Florence, Italy, Catherine witnesses her dreams shattered, her future as ruler in Florence betrayed.

Guilio de Medici, Pope Clement VII, has other plans for his niece: a political marriage to the French heir to the throne. Arriving in Paris for her betrothal, Catherine views Henri’s father, Francis I, as a father. But as politics would dictate, events conspire to thwart her plans once more. Ever in thrall to mathematics and the study of astrology, Catherine seeks answers through a practitioner of the dark arts, Cosimo Ruggieri. While Cosimo promises to deliver her to success at the price of the blood of innocents, a desperate woman succumbs to what she believes is her only course of action to protect her sons on the throne.

The author weaves the machination of politics with Catherine’s determined efforts to retain power gained through marriage to Francis’s heir. From the revolution in Florence when she is eight years old to the growing clash between Catholicism and Protestantism that throws France into civil war and senseless bloodshed wrought of religious intolerance, Catherine cuts her teeth on intrigue, loyalty, betrayal, and the fickleness of kings.

As Henri’s queen, Catherine fights to hold sway with her husband in spite of crippling humiliations, fueled by the dark visions of nightmares that haunt her nights. Invoking spells and charms, Catherine embraces the forces of evil. It is to the author’s credit that Catherine’s impulsive actions are believable, driven as she is to protect France and her sons. A woman in a court that disdains female weaknesses, Catherine is an impressive counselor, ruling by Henri’s decree as regent after his death.

As religious conflicts escalate, two unstable young kings are saved from the brink of disaster by their mother’s interference: “I learned early that I was capable of murder.” While it seems ludicrous that Catherine could affect affairs of state with myths and incantations, in pre-Revolutionary 1527 the tenor of the country is unsettled. The court is riddled with deceit, a slow violence simmering throughout the country as Huguenots and Catholics prepare for battle, each fighting God’s war at the cost of thousands of lives, culminating on the St. Bartholomew’s Day Massacre in 1530, the result of the most stinging betrayal of all.

The distrust, unrest and jealousy are palpable in the years Catherine’s sons reign, the remarkable Catherine confronting all who threaten the succession of Henri’s natural heir. But hubris brings many a proud man to his knees, even a queen, as events propel France to the very gates of hell in civil war. As surely as the dark arts swirl around Catherine’s footprint in history, the evolution of religion and politics breeds bloody conflict. Catherine is an intimate witness to greatness and courage, fate never really in the hands of mortals.