Traditional Italian suits have just the jack, knight and king:
German suits usually have two jacks, the under and the over, and the king (with a horse or not):
And of course, the best known French suits have a king, a queen and a jack:
Those systems have obviously influenced each other, but in what way exactly? From the superficial knowledge I have, I think it was like this:
* The military system with king, knight and jack is the most original one, rather directly taken from Mamluk predecessors with king, deputy king and 2nd deputy.
* The same is the case for the German suits (I don't know to what degree they are descendants of the Italian suits, or more directly of Mameluk suits).
* To better represent the court, in later games including tarot a queen was added.
* The modern French suits developed to a stricter representation of the court, reducing the military order, and thus removing the knight.
* Today, there are many games played both with French suits and either German or Italian suits. In those games, the "French" queen is identified with the "Italian" knight or the German over for obvious reasons, even though this is historically incorrect and strange enough in the "marriage" group of card games.
What do the experts say?