Who are the four kings in a deck of cards?

Who are the four kings in a deck of cards?

Card games attract players from around the world for centuries but in the last decade, thanks to the internet, the poker game became a recreational sport played by millions every day. The history of poker game is not very clear, but one thing is certain: playing card started to be used in the late fourteen century.
When it comes to the design of the cards there is one major dispute: do the four kings represent great historic rulers and who are they?
Is a common belief that the four royal cards represent David (King of Spades), Alexander the Great (King of Clubs), King Charlemagne (King of Hearts) and Caesar Augustus (King of Diamonds). This belief seems to be contradicted by the history itself.
Around 16^th century French card games players made some changes to the cards, making them to look very close to what we use nowadays. They adopted the four suits that we also use today, spades, hearts, diamonds, and clubs, each representing a class: nobility, clergy, merchants and peasants.
Around that time the cards makers started to assign identities to the royal cards and printed them on the cards. The royal cards identities where different, depending on the manufacturer’s personal choice.
Once the French Revolution came in the 18^th century, card manufacturers gave up writing kings names on the cards because the monarchy was no longer welcomed in France. The French model of card games was the most successful and was adopted throughout the world by the card games fans. In conclusion, the royal cards that we use today in card games do not represent any particular king figure.