Privy Chamberlains to His Holiness
The date of institution of this class is unknown; it probably developed by degrees as an honor for priests who had rendered signal service in missions representing the Holy See; since 1800 it is a simple honorary title.
Their number, which is variable, is at present 1728.
The offices of these and of all other divisions of chamberlains cease at the death of the pope who appoints them (in this case titles are suspended during the vacancy of the Holy See), but reappointment is customarily made through the medium of the majordomo on the election of the new pope.
New Catholic Dictionary