The Pontificial Equestrian Order of Saint Gregory the Great is one of five orders of chivalry that are bestowed by the Papacy. Its members are Catholic laymen and women deemed to have contributed greatly to the Catholic Church; men receive the title of Knight, and women, of Dame.
The Order has four classes in civil and military divisions:
- Knight / Dame Grand Cross of the First Class (GCSG / DCSG)
- Knight / Dame Commander with Star (KC*SG / DC*SG)
- Knight / Dame Commander (KCSG / DCSG)
- Knight / Dame (KSG / DSG)
The Order was created by Pope Gregory XVI (1831-1846) on September 1, 1831. It is named after his namesake Pope Gregory I (590-604).
Nucky Thompson is made Knight Commander of the Order of Saint Gregory the Great by Pope Pius XI on December 12, 1922. The ceremony of acceptance is set to take place in Atlantic City's Saint Finbar's Church on January 9, 1923. ("Spaghetti and Coffee")
While Nucky is unwilling to attend the ceremony (the knighthood being a reward for donating the lands favored by the 1921 Road Appropriation Bill to St. Finbar's Church, which was actually done behind his back by Nucky's wife, Margaret Thompson), Margaret convinces him and he receives the Order's insignia from Father Shocke. She also arranges for a reception with Bishop Norman after the ceremony in order to manipulate Dr. Robert Landau into opening a women's health clinic in the Catholic Church-run Saint Theresa's Hospital. During the reception Margaret's neighbor Cornelia Predock jokes that since Nucky is a knight now she'll have now to clean his armor. ("Bone for Tuna")
The knighthood is referenced again in Easter Sunday, when Eli asks Nucky if he had to make a confession before being bestowed the insignia. He says that that is only required for "the people in steerage". ("Sunday Best")