Books like Spy princess by Shrabani Basu

"Six gentlemen, one goal: the destruction of Hitler's war machine. In the spring of 1939, a top-secret organization was founded in London: its purpose was to plot the destruction of Hitler's war machine through spectacular acts of sabotage. The guerrilla campaign that followed was every bit as extraordinary as the six men who directed it. One of them, Cecil Clarke, was a maverick engineer who had spent the 1930s inventing futuristic caravans. Now, his talents were put to more devious use: he built the dirty bomb used to assassinate Hitler's favorite, Reinhard Heydrich. Another, William Fairbairn, was a portly pensioner with an unusual passion: he was the world's leading expert in silent killing, hired to train the guerrillas being parachuted behind enemy lines. Led by dapper Scotsman Colin Gubbins, these men--along with three others--formed a secret inner circle that, aided by a group of formidable ladies, single-handedly changed the course Second World War: a cohort hand-picked by Winston Churchill, whom he called his Ministry of Ungentlemanly Warfare. Churchill's Ministry of Ungentlemanly Warfare is a gripping and vivid narrative of adventure and derring-do that is also, perhaps, the last great untold story of the Second World War"--

Prince Florence secretly conspirators, but Princess Margaretha's fateful switch sparks a romance that revives hope for her father and Hagenheim Castle.

During the American Civil War, Quaker-educated aristocrat Elizabeth Van Lew risks her life pledging loyalty to the North, using her intelligence skills to aid Richmond’s underground network and orchestrate daring escapes from Confederate Libby Prison.