Percival Sheldrake was born in 1888 to an old British aristocratic family. He devoted himself to all the things those of his class were expected to do, becoming well spoken and a good fighter. He distinguished himself in Burma and his career climbed up from there. When an ancient Knight of the Round Table appeared in modern day (fulfilling an old British Legend), Sheldrake was able to climb to the top of a pool of candidates to join Sir Justin's newly formed military unit.
Percival was a close friend of Sir Justin, helping him adjust to modern life and military tactics. He was also a father to his men, most notably hiring and training Alfred Beagle into his squadron. He would pioneer many tactics which are now commonplace among black ops units across the world.
After Sir Justin's death fighting Vandal Savage in 1916, Percival was chosen to don Justin's armor in an attempt to keep morale up (seeing the "Knight" out there kicking British ass). He would go from there to a more ceremonial position as a bodyguard for British officials following the war, occasionally going out on military missions and authoring multiple books on future military policy.
Percival had a son named Cyril in 1926. He was assassinated in September 1939 by Ra's al Ghul briefly before being called in duty by Her Majesty's Government for a recon mission in Poland. Still, his final scholarly paper on military tactics would become the blueprint for the founding of the Special Air Service, Britain's premier black ops unit.