How did the J, Q, K and A of playing cards come from?

There are two theories about the origin of poker: ancient Egypt and ancient India. At that time, it was a divination card, which was also a tarot card. The original tarot cards were composed of numbers and characters. J is jack, that is, knight; Q is QUEEN, that is, the queen; K is king, that is, king; A is the first one. That's it.