For whatever reason, we read up on the history of playing cards, the evolution of suits and ranks. Did you know that there were once knights between queens and jacks? Or that Germans replace queens with officers? Or that the Jack of Clubs possibly represents Judah Maccabee? Oops, we just got ahead of ourselves!
In any case, the playing cards we know today derive from the French model. And back in the 15th century, they decided to give names to the face cards. For example, the King of Hearts was usually Charlemagne, and the King of Spades, David. (Score one for the Jews!) Caesar (diamonds) and Alexander (clubs) rounded out the quartet.
We'll skip over the queens (just like those pesky Germans), for their identities are not clearly interpreted, and discuss the jacks. Here we have military leader La Hire (hearts), Charlamagne's fictional paladin Ogier (spades), Hector from the Iliad (diamonds) and good old Lancelot (clubs). They truly are over the map here, from ancient Trojans to Arthurian legends to the very real La Hire, who commanded the French Army during the 100 Year War.
Wait, didn't we say Judah Maccabbee? That we did. Apparently, some versions had him substitute for Lancelot. Good for the French to be so inclusive, we guess.
In any case, when the French Revolution hit, royal symbolism quickly disappeared from the decks, and that was it for Maccabee and his pals.
Probably for the best that Germans didn't name their cards...