The King of Spades is theorized to represent King David. In Tarot Motifs, the King of Spades is viewed as a stern, dishonest lawyer.
The King of Hearts is theorized to represent Charlemagne. Traditionally, this card is shown with a sword over his head, giving him the nickname "suicide king." Interestingly, this is the only king with no moustache.
The King of Clubs is theorized to represent Alexander the Great. When crossed over with Tarot Motifs, he is said to represent loyalty, integrity, and being unaware of having great power.
The Queen of Spades, popularly representing Pallas Athena. In the game Hearts, she is considered unlucky; whoever gets the Queen of Spades gains 13 points to his detriment note Points are bad in Hearts. Unless a player obtains her with all 13 hearts, in which case he shoots the moon and everyone else gains 26 points. She is the titular Old Maid in the game Old Maid. Tarot Motifs have her as an intelligent, tactical woman, befitting the goddess she was supposed to represent.