The very powerful and revered Hanuman Chalisa’s existence is attributed to Swami Tulsidas, a poet-saint who lived in the 16th century. Tulsidas was a very learned poet and devoted saint. He had all the worldly knowledge. It is believed that Tulsidas was the reincarnation of Valmiki, the composer of original Ramayana.
According to the legends, one day, after his bath, Tulasi Das was returning from the river. On his way back his home, he was hit by a blind man. Seeing the blind man, Tulsi Das wished that gains his eyesight. And since Tulsi Das was a great devotee, his wish came true and the man got his eyesight. The whole incidence was reported to the Mughal Emperor, Akbar.
The King’s men said that Tulasi Das is a magician. The Mughal King was intrigued and wanted to witness his magical powers. King Akbar invited Tulsi Das to his court to show him his magical powers.
To which he replied that “it was God’s grace which made the blind man regain his eyesight” King got angry and was about to order that he be punished.
Thus Tulsi Das was imprisoned. It was in the prison when Tulsi Das started writing Hanuman Chalisa. Hanuman Chalisa is a 40 verse epic. It is said that when Tulsi Das completed Hanuman Chalisa on the 40th day, the entire Fatehpur Sikri was surrounded by giant monkeys. They created havoc all around the town, so much so that Akbar ordered to free Tulsi Das of captivity. As soon as Tulsi Das was released, the monkeys went, clearly indicating that Lord Hanuman came to the rescue of Tulsidas.
Since then, it is believed that chanting Hanuman Chalisa in danger will free you from the danger and evil spirits.