Short answers, pulled from the story.
The King's Royal Rifle Corps was established by an act of Parliament that passed on the 4th of March 1756. Although approval was granted just before Christmas 1755, administrative delays meant the special act creating four battalions of one thousand men each did not pass until the 4th of March 1756.
Jacques Prevost was the true architect of the King's Royal Rifle Corps, while the Earl of Loudoun served as colonel-in-chief. Henry Bouquet was a distinguished foreign officer whose forward-looking ideas on tactics and training eventually became standard in the British Army.
The King's Royal Rifle Corps fought in major conflicts including the Battle of Mons, the First Battle of the Marne, the First Battle of the Aisne, and the First Battle of Ypres. Additional engagements included the Battle of the Somme, the Battle of Arras, the Battle of Cambrai, and the Hundred Days Offensive.
The King's Royal Rifle Corps changed its name to The Duke of York's Own Rifle Corps in 1815 and then to the King's Royal Rifle Corps in 1830. In 1958, it was brigaded with other regiments to form the Green Jackets Brigade, and in 1966, it was amalgamated to form the Royal Green Jackets.
The 1st Cadet Battalion of the King's Royal Rifle Corps was founded by the Reverend Freeman Wills, who was commissioned into the Volunteer Army on the 26th of July 1890. Consent to affiliate the unit to the regiment was granted on the 8th of November 1894.