Charlemagne did not intentionally stab himself in the head.

Consider your average deck of cards.  No matter where you get ‘em or what brand you buy, they’ll be the same uniform set.  How’d that come about?  Glad you asked.  It was the Italians who brought playing card into Europe in the 1300’s.  The Frogs standardized the first modern set at Rouen in 1565.  King James patented and standardized them in 1611 (the same year he updated and standardized his King James Bible, thus forever linking sinful gaming and salvation).  After the Civil War, the Americans created the version that is still current today.

It’s likely that the deck was supposed to represent the 52 weeks of the year, broken into four seasons (suits), ruled over by various Jewish, Greek, Roman and Medieval nobles, who may also represent the 12 signs of the Zodiac.  The Kings are largely believed to be David (Spades), Charlemagne (Hearts), Caesar (Diamonds) and Alexander (Clubs).  The Queens are the Greek Minerva, Judith of France, and Rachel. The fourth is Argine, an anagram of “Regina” meaning “Queen.”  The Jacks are Ogier, who was a knight of Charlemagne, La Hire, who was a buddy of Jean D’Arc, Hector of Troy and Judas Maccabee.

But beyond that, the deck is a result of happenstance and error:

• Jacks were originally called Knaves, but it was confusing to have both “K”s and “Kn”s in the corners, so a term was stolen from the game All Fours, where the Knave of the trump suit is called the Jack.
• Originally a “one”, the term “Ace” comes from the smallest Roman coin, the “as”.  Aces became more powerful than Face Cards after the French Revolution, to symbolize the power of the common man over the King.
• The Ace of Spades is the only card that’s certain, since it represents Death and Taxes.  It was the card historically stamped by the crown to verify a tax had been paid, so all makers today use that card for their copyright.  It has also come to mean death in many societies.  For example, during the Vietnam War, the American military scattered them throughout the jungle in an attempt to scare the VC.
• The Joker is an American invention, naturally.  It was brought in as the highest card in Euchre, also pronounced “Juker,” and evolved from there.
• The “orb” held by the King of Clubs originally represented Caesar’s control of the earth; Caesar and Alexander later flipped suits.
• The nine of diamonds is “The Curse of Scotland” but nobody can really remember why.
• The four of clubs is “The Devil’s Bedpost”; it does look like a four-poster but the sinister origins are unknown.

As for Charlemagne, that was a mistake.  The “suicide King of Hearts” originally wielded an axe like the King of Diamonds, but a bad print job resulted in later designs that ran a blade through his head.  Thus, art directors are the source of all error, or the source of all power, depending on how you look at it.