There is a myth behind celebrating this festival. The legend says that Mandodari, the wife of the great Ravaan had great devotion towards the Goddess Chandi and to honor her she built a temple at Meerut. Meerut was also her birth place where she was born in a demon's house. Ever since that time, this festival has been observed by the people that has religious connotations. It usually takes place in the month of February and March.
Whenever there is a talk about the Nauchandi Fair (Nav Chandi Fair) there is the mention of the 10 great learning which is all related to Shakti or mother Parvati who is also known by other names such as the Navdurga, Sati, Chamundi, etc. The fair is about trading of the cattle but during this time Goddess Parvati and her different forms are also worshipped. The story of the 10 different forms is something like this. It is said in Hindu mythology that when King Daksh Prajapati invited every other kings and Devtas but his own son in law for a Yagna, Sati was angry that she and her husband wasn't invited by her father. She insisted on going there but Lord Shiva didn't allow her to go for they didn't receive any invitation. At this Sati was angry and took the form a dark energy. Lord Shiva tried escaping from such rage and at this in order to stop him from 10 different directions she took the form those ten different forms. These ten different forms are Kali, Tara, Chhinnamasta, Shodashi, Bhuvaneshwari, Tripura Bhairavi, Dhumavati, Baglamukhi, Matangi and Kamala. These ten different forms of Parvati is called the 10 different learning and are considered the real powers of Lord Shiva.
The event is a grand one where people come to see different kinds of domesticate animals and some of them also make a good bargain and purchase very good and healthy animals. People from all over the state and also from neighbouring states of Uttar Pradesh reach the event to take part in it. The place is filled with great energy and one can notice the enthusiasm and excitement on the faces of the cattle owners. Besides the stalls put up for cattle there are other types of stalls too where the traditional handicrafts are sold and could be one of the sweet souvenir for you to take back home.