In the Middle Ages learning, and even literacy, were not considered necessary acquirements for a great lord. The qualities expected of him were bravery, dash, a certain magnificence and easiness of style, perhaps the practical sense of a man of the world, but not learning. Such men set the pace for lesser landowners, and their style tended to be imitated even by those who had made money as lawyers, merchants, or sheep farmers. The reactions of one particular gentleman, as reported in the early sixteenth century, were reasonably typical: “I’d rather that my son should hang than study letters. For it becomes the sons of gentlemen to blow the horn nicely, to hunt skilfully and elegantly, to carry and train a hawk. But the study of letters should be left to the sons of rustics.”

Mark Girouard, Life in the English Country House

Some exceptions: Duke Humphrey of Gloucester, younger son of Henry IV; Richard II; Thomas Percy, Earl of Worcester.

I don’t even mean to make the easy dunk (or other football-appropriate pun) on Kelce; I actually find it quite admirable for a celebrity to cop to their own illiteracy in a country where more than half the adult population reads below a middle school level. The Girouard quotes come from Helen DeWitt’s blog, where she argues that today

programming occupies a place similar to that of literacy in mediaeval England. It is necessary both for government and for business at all but the smallest level, but it is not a skill whose lack would be shameful in anyone with pretensions to social standing. On the contrary, it is associated with qualities of character that carry no prestige, are even socially stigmatised (we may think of the way Mark Zuckerberg is presented in The Social Network). One can get a lot of mileage out of deploring grammatical ignorance, especially in public figures; one can get a lot of mileage out of ranting over deprecated punctuation; one wouldn’t get very far deploring ignorance of the difference between a number and a string, haphazard use of white space or of capitalisation in the naming of functions and variables.

DeWitt further mentions she doesn’t “know whether such ignorance will ever be an embarrassment to a presidential candidate,” but of course illiteracy is low on the lost list of things that won’t embarrass a presidential candidate.