Near the end of Bring Up the Bodies, the second novel in Hilary Mantel’s Tudor trilogy, Anne Boleyn’s executioner picks up her head from the scaffold and “in a yard of linen he swaddles it, like a newborn.” Thomas Cromwell, King Henry VIII’s secretary, who orchestrated Boleyn’s demise, is left fearing that he may soon fall victim to his enemies’ manipulation of the king’s fluctuating affections. But Cromwell decides to dig in. “Let them try to pull him down,” Mantel writes. “They will find him armored, they will find him entrenched, they will find him stuck like a limpet to the future.”

The Mirror and the Light, the third and final book in a series that began with Wolf Hall in 2009, is another crowded Tudor panoply viewed entirely through the eyes of Cromwell, whose nature is as labyrinthine as the palace corridors he superintends. Festooned with new titles and heaped with new properties, he is a widower “too useful to be sad,” at least for long, and a compulsive seeker of advantage who will always “glance around a room to note the exits.” He is not one of those men who “can make a tidy parcel of their past.” Amid all the marital and theological calamities unleashed by the king, Cromwell is ever agitated by childhood memories of his brutal blacksmith father; his youthful days in Europe as a mercenary soldier and fixer; and his later service to Cardinal Wolsey, the all-powerful Lord Chancellor who was finally brought low by Henry. “My master Wolsey taught me, try everything,” Cromwell says. “Discard no possibility. Keep all channels open.” Past so inhabits present that Mantel includes the dead in the trilogy’s dramatis personae.

Henry’s court is a little world of terror, more Orwellian than antique for all of Mantel’s splendid period ornamentation. Fantastic rumors and royal whim generate its weather. Falls from grace are sudden and frequently fatal. On the throne for a quarter century by now, Henry is a very human Big Brother, not without shame but bathed in self-pity, and reaching new heights of grandiosity. Hans Holbein finds the king easy to paint because “his face shines with the wonder of himself.” Nonetheless, his body is turning gross and feeble. Cromwell keeps a secret Book of Henry, a kind of customized version of Machiavelli’s The Prince, in which he can devise strategies for coping with his monarch’s vanities and moods.

Threats to Henry’s reign come from within the royal enclosures as well as from afar. Reginald Pole — a descendant of the once-ruling Plantagenets, who regard the Tudors as arrivistes — now spreads heresy and treason on the Continent. The French king wants to wrest Calais from the English, even if he has to ally with the Holy Roman emperor, Charles V, to do it. And a tax rebellion has begun in the northern reaches of the realm. Still, nothing can long distract Henry from the altar. Jane Seymour, his third wife, as pliant as Anne Boleyn was petulant, at last produces the male heir that Anne, and Katherine of Aragon before her, did not. But the effort kills her, and Henry is urged to father a backup male via a fourth wife.

Even with his overstuffed portfolio, Cromwell makes time, and room in his household, for a procession of “roaring boys” — “runaway apprentices, roisterers, ruffians” — in whom he sees the combination of hard knocks and gumption that led to his own rise in the world. There is a tenderness in him that extends even to those he must ruin or kill or threaten with torture. Some of this novel’s best moments have him sparring with Mary, Henry’s Catholic daughter with Katherine, pressing her to swear obedience to her father rather than risk being used by those seeking to undo Henry’s self-interested English Reformation.