(Parliamentarian news pamphlet, 1645, warning of Royalist spies; quoted in Akkerman 2018, 64-5)

Lady d'Aubigny continued her intelligencing work while Charles was imprisoned, and was involved with one of the several failed escape attempts leading up to his eventual execution. While Charles was being transported to Hurst Castle in December 1648, he called upon Katherine and her new husband, James Livingston, Viscount Newburgh, at their home in Bagshot, Surrey. Surprisingly, Parliament had allowed Charles to dine with them, despite the knowledge that Katherine was a Royalist agent; however, the window of opportunity did not close in their favor. The Newburghs' plan to give Charles one of their horses, the fastest in England, did not fool his captor. The king failed to escape, and went on to his impending doom (Akkerman 2018, 27-8).

Eventually, Jane turned to the intelligence trade. She was involved in courier work, particularly conveying correspondence to Charles while he was imprisoned. Sir Lewis Dyve, a Royalist intelligencer, names Jane and a "Mistress Windam" as rwo agents that he used to send letters to the king while imprisoned in the Tower of London (Akkerman 2018, 39-40). Jane would also become a key figure in Charles' numerous escape attempts, planning and participating in many of them herself.

While many Royalist agents were ladies of the court, they also employed lower-class women. John Barwick, an Anglican clergyman and Royalist spy, ran a clandestine ring of female couriers who transported illicit materials between Oxford and London (Smith 2011, 42-4). These women smuggled letters concealed in books between the two cities. Barwick's brother Peter made note of the "Meanness" of the women's conditions, which made them less conspicuous than the high-profile ladies serving the king (Akkerman 2018, 29). One of the possible routes used by Barwick's couriers involved traveling up the Thames to the town of Henley, and from there proceeding overland to Oxford. Two women named by the Mercurius Civicus, Mrs. Penyall and Mistress Guy, served similar courier functions between Oxford and London, although likely not employed by Barwick (Smith 2011, 44). Richard Royston, a collaborator of Barwick's, also organized the distribution of the Royalist publication Mercurius Aulicus by female couriers in London (Smith 2011, 44-5).

Lucy Percy, Lady Carlisle, was one of the most formidable spies of the English Civil Wars; her exploits were so prolific that she was likely the inspiration for Milady de Winter in Alexandre Dumas' The Three Musketeers. Like Milady de Winter, she was what many might consider a femme fatale, and incredibly efficient in her work. However, she was no assassin, and in the end escaped the grim fate of her fictional counterpart (Akkerman 2018, 7).

"Independent, invisible, apparently impossible to punish, it seems obvious with hindsight that women should make excellent spies: the only question that remains is why there were not more of them. The answer, of course, is surely that there were, we simply have not caught them yet."