Percy Sheldrake was only 20 years of age when his mother was killed in the bombing raid in London and his father was captured during the Dunkirk Evacuation. The Shining Knight failed to save Percy's parents, so he took Percy as his Squire. Percy received enchanted armor from the Shining Knight. This armor would protect him from swords and projectiles. He taught Percy, so that one day Percy would be a knight. Percy fought alongside the Shining Knight for the rest of WWII. He was also on a team of younger superheroes known as the Young Allies. They fought in Europe until their differences pulled them apart. Percy eventually gained enough skill to advance in his rank to become the Knight, taking his son, Cyril, as his Squire.
Percy is killed when he faces his nemesis Springheeled Jack. He is forces to swallow a bomb and his son takes the mantle of the Knight.
Percy Sheldrake, the original Knight, first appeared in December of 1950 in Batman #62 created by Bill Finger and drawn by Dick Sprang. In later comics, Roy Thomas and Michael Bair are responsible for creating his backstory as the first Squire.