The story of Nataraja has a mythological origin and narrates how the form of Lord Nataraja came up first. The town of Chidambaram is adjacent to Pichavaram which is marshland and home to two estuaries occurring at the points of where two rivers namely Vellar and Cooleron merge with the Bay of Bengal.
The region had a thick forest dominated by Thillai Trees (Excoecaria agallocha). These are a species of mangrove trees. The thick forest is home to a lot of plant, animal and bird species in addition to a lot of sages engaged in the life of penance.
A group of sages who inhabited the forest was fully engrossed in black magic and ghastly rituals. They believed that God can be controlled by magic wands, rituals, and mantras. Their ways and philosophies were neither useful to them nor benefiting others.
They had grown unsympathetic and even harmful to others often troubling anybody and everybody who came on their way. Lord Shiva wanted to put an end to their atrocities and also put them in the right path to salvation. Therefore he assumed the form of a wandering beggar or mendicant known as Bikshadana.
Bikshadana was naked. He was of awesome beauty and brilliance. Lord Vishnu disguised as Mohini, the most beautiful feminine form followed him. The mesmerizing beauty of Bikshadana charmed the wives of the sages who lost their senses and started following him. The sages were shocked to see what was happening in front of their eyes and so, started using their magical powers to attack Bikshadana not knowing that he was, in fact, Lord Shiva in disguise.
The sages performed magical rituals and released scores of dreadful serpents on the Lord. The Lord gathered all of them and wore as ornaments. They released a fierce looking tiger endowed with magical powers. Shiva just tore the skin of the beast and wore it around his waist. Then an elephant came out of the sacrificial fires and rushed towards the Lord which was ripped to death by Bikshadana.
Then the sages grew highly concerned about the developments and gathered all their powers and gave birth to a demon called Apasmara. He was a symbol of arrogance and ignorance. Now the Lord effortlessly stepped on the demon’s back and started dancing.
The Ananda Tandava or the ecstatic dance of Lord Shiva now revealed him in his true form to the sages. The divine vision they had removed their ignorance and made them understand that it was none else than Lord Shiva and they had been resorting to bad ways all the years gone by.
The place of this divine miracle of Lord Shiva later gave rise to the most famous temple of Chidambaram. With the participation of several rulers and dynasties, the temple was developed in a magnificent manner. To this day, the temple has been one of the most popularly visited places for the devotees of Lord Shiva and was also visited and sung by many Shivite saints. Lord Nataraja thus dances ecstatically in order to remove the ignorance and bondage of humans.