Books like One Night With a Spy (Royal Four) by Celeste Bradley

Lord Giles Cardross believes his 18‑year‑old wife, Helen, loves him, but her frivolous ways and rising debts make him question whether she married for money. Family scandals and hidden truths threaten their union.

Emily Portsman hides a dangerous secret while working at London’s forbidden Tantalus Club. When former spy Nate Stokes, the Earl of Westfall, hunts a murderess, the two find trust, desire and deadly intrigues amid eighteenth‑century Great Britain.

A historical romance set in 16th century England, featuring Lorna Doone, a young woman who is kidnapped and becomes a fugitive during the Monmouth Rebellion.

A British soldier and a war-weary rebel find themselves entangled in a dangerous game of espionage and passion, risking everything to be together.

Alicia Lawrence, exiled from polite society, poses as the mistress of Lord Wyndham to uncover a conspiracy threatening her county, while a passionate liaison turns their uneasy partnership into a thrilling spy romance.

Olivia Greenleigh’s blissful marriage to spy Dane Calwell turns perilous when he refuses to explain his secret work—forcing her to uncover a dangerous plot that could tear them apart.

New York Times bestselling author Jane Feather has won legions of fans and critical accolades for her sweeping romances portraying a unique blend of sizzling seduction and dangerous intrigue. In this first of two romances featuring two unconventional sisters whose quest to solve the mystery surrounding their lives puts each of them in the path of a dangerously irresistible hero, Jane Feather tells the story of a daring young widow and a master spy engaged in a duel of wits--and seduction--to uncover a dark secret....To Kiss a Spy Lady Pen Bryantson had been caught red-handed looking for clues among her mother-in-law's papers. But the mystery she sought to uncover only deepened with the sudden appearance of a man whose mere presence sent shivers of excitement coursing through her. What could this dangerously seductive man who moved with a courtier's charm and brandished an assassin's skill want with someone as ordinary as she was? But to Owen D'Arcy, the bewitching young woman he'd been assigned to ensnare was anything but ordinary. With a single kiss, the sophisticated spy found that he'd been unexpectedly disarmed. Determined to seduce her on his own terms, Owen offered Pen a devil's bargain she had no choice but to accept. Now they would both go undercover, only to find themselves drawn into a world of deception and double cross, where anyone could be the deadliest of enemies--and their own uncontrolled passion the most dangerous threat of all.From the Paperback edition.

Willa Trent, a high‑born orphan, is thrust into a hurried marriage with Lord Nathaniel Stonewell, the Earl of Reardon, who hides a dangerous spy identity.

Through the eyes of Henry IV’s youngest son, John of Lancaster, Georgette Heyer portrays the turbulence of late‑14th‑century England, blending court intrigue, warfare, and the personal ambitions of a youthful prince.

After years abroad, Royal returns to a dying duke and a nearly empty treasury. He must marry heiress Jocelyn Caulfield, but his heart is drawn to her cousin Lily Moran, who schemes to recover the estate’s fortune together.

An empress of Austria, a penniless English horseman, and a clever heiress entwine in a love triangle set against the 19th‑century Grand National, exploring the private yearning behind public duties.