Girdwood served as a Captain in Ireland during the United Irish rebellion of 1798. While on patrol he became lost and was ambushed. The court of inquiry at Dublin Castle dismissed him on half pay, effectively ending his military career. Some 10 years later Girdwood was recruited by Sir Henry Simmerson, whom he had taken his reprimand to, and Lord Simon Fenner, who promoted him to Major, and then to Lieutenant Colonel and appointed him to command Second Battalion of the South Essex Regiment, a cover for an extensive financial fraud and crimping scheme. Girdwood is also betrothed to Simmerson's orphaned niece, Jane Gibbons. The scheme is discovered in 1813 by, Major Richard Sharpe, when he returns to England seeking reinforcements for the Regiment's First Battalion in Spain. With the help of Regimental Sergeant Major Patrick Harper, Sharpe, under an assumed identity, tracks the South Essex's recruiting parties to a secret training camp on Foulness Island, where he observes the new recruits being brutalised, cheated and auctioned to other, less popular regiments. When Harper intervenes to protest the summary execution of a deserter, he and Sharpe are hunted through the Foulness marshes by Girdwood and his fellow officers. Sharpe returns to the camp and removes Girdwood from command. Girdwood escapes and Sharpe attempts to follow his trail to evidence that will implicate Simmerson and his allies in Government. After discrediting Simmerson and saving the Battalion, Sharpe retains Girdwood as the nominal commander of the South Essex. On his first experience of battle, a relatively minor engagement in the Pyrenees, Girdwood suffers a complete mental breakdown and is invalided home.