Akbar was the Mughal King and Birbal was the (Wazir-e Azam) of the Mughal court in the administration of the Mughal emperor Akbar. He was one of his most trusted members along with being a part of Akbar's inner council of nine advisors, known as the navaratna, a Sanskrit word meaning nine jewels. Birbal was one of only a few persons other than Akbar that were Din-i-Ilahi believers.
Birbal's duties in Akbar's court were mostly military and administrative, but he was also a very close friend of the emperor, who appreciated Birbal for his wit and wisdom, often involving humorous exchanges. These and other stories have become part of a rich tradition of folklore and legend.

So here check out one story "The Strange Letter"