Prince Prospero's name indicates what social class he is in. So, he invites other members of the privileged class: "a thousand hale and light-hearted friends from among the knights and dames of his court."
Like many wealthy and privileged people, Prospero is "happy and dauntless and sagacious." He feels that his wealth and social standing would exclude him from disease, the "Red Death." The abbey is fortified with lofty walls and gates of iron. No one is allowed in or out once the gathering is assembled; consequently, the prince and his guests believe themselves protected as Prospero himself from material harm.