
The fourth avatar of Bhagavan Shri Vishnu is called Lord Narasimha. Lord Narasimha is depicted as a half-man, half-lion form and is considered a powerful and fierce incarnation of Lord Vishnu. This avatar is associated with the purpose of protecting and restoring dharma (righteousness) and destroying evil forces. Lord Narasimha is often revered for his courage, strength, and devotion to devotees.

Lord Narasimha is one of the most popular avatars of Vishnu, and his story is often told in Hindu mythology. The story goes that Hiranyakashipu, a powerful demon king, had become arrogant and tyrannical. He demanded that everyone worship him as the supreme god. His own son, Prahlada, however, remained a devout devotee of Vishnu.

Hiranyakashipu was furious, and he tried to kill Prahlada in many ways, but Vishnu protected him each time. Finally, Hiranyakashipu challenged Vishnu to appear before him in a form that was neither man nor animal, neither inside nor outside, neither day nor night, and neither on the ground nor in the sky.

Vishnu appeared as Narasimha, a half-man, half-lion creature. He killed Hiranyakashipu at dusk, on the threshold of his palace, in his lap, and with his claws. This form of Vishnu was specifically designed to fulfill all of Hiranyakashipu’s conditions, and it was thus a perfect way to defeat him.

The story of Narasimha is a reminder that Vishnu will always protect his devotees, even from the most powerful of enemies. It is also a reminder that evil will always be defeated, no matter how strong it may seem.

Nrisingha (Narasingha/Narasimha) Deva is indeed the fourth Avatar of Lord Vishnu. He is depicted as a half-man, half-lion being, where his head and upper limbs resemble a lion while his torso and lower part of the body are human.
According to Hindu scriptures, Lord Vishnu has appeared in nine different Avatars or incarnations throughout different ages, and the tenth Avatar (Kalki Avatar) is yet to manifest. The nine Avatars of Lord Vishnu that have already appeared, in chronological order, are: Matsya (Fish), Kurma (Tortoise), Varaha (Boar), Nrisingha (Half-man half-lion), Vamana (The dwarf), Parasurama or Bhargava Rama, Lord Rama or Dasharathi Rama, Balarama, Krishna, and Buddha.
The first four Avatars (Matsya, Kurma, Varaha, and Nrisingha) appeared in the Satya Yuga, the next three (Vamana, Parasurama, and Lord Rama) appeared in the Treta Yuga, and the final two (Balarama and Krishna) appeared in the Dwapara Yuga. The tenth Avatar, Kalki, is said to appear at the end of the Kali Yuga.
While this is the standard list of the ten Avatars (Dashavatara) of Lord Vishnu, there are some controversies and alternative beliefs. Some consider Lord Krishna to be Lord Vishnu Himself and not one of His Avatars. Additionally, there are differing opinions that place Lord Jagannath or Lord Buddha as the ninth Avatar of Lord Vishnu.
Although Vishnu (or Krishna) temples can be found worldwide, featuring various deities, it is not common to find separate temples dedicated to each of the ten Avatars. Temples dedicated specifically to Nrisingha Deva, the fourth Avatar, are relatively rare in comparison.
In India, there are only a few temples dedicated to Nrisingha Deva, and a list of such temples can be found in Appendix II.