CHITHIRAI THIRUVIZHA-Meenakshi kalyanam, the HISTORY of combination of two celebrations

The Meenakshi Tirukalyanam festival, also called Chittirai festival, is celebrated during April–May every yearv for 10 days.

Two different versions of stories exist as the history behind the celebration,

1.THE STORY BELIEVED BY THE NATIVES

It is believed that the Lord Vishnu, as Alagar, the brother of Meenakshi rode on a golden horse from Alagar hills to Madurai to attend the celestial wedding of Meenakshi (Parvati) and Sundareswarar (Shiva).
Before Alagar reaches the wedding, the marriage will be completed and he does not cross the vaigai river. 
This delay was purposely caused by Lord Shiva, and he himself took form of Lord Alagar and performed the "Kanyathanam" of Devi Meenakshi. This was enacted by Lord Shiva to show the World that Vishnu (Alagar) and Shiva are one and the same.
Alagar decided to give all the gifts that he carried to Meenakshi and Sundarishvar in a Mandapam in the middle of the Vaigai river, and returned to Alagar Hill without entering Madurai.

2.THE ACTUAL HISTORY

Meenakshi Kalyanam and Alagar festival were rwo different festivals celebrated during different months.

Meenakshi Kalyanam was orginally a SHAIVAITE celebration while the Alagar festival was celebrated by the VAISHNAVAITE.During the rule of king THIRUMALAI NAYKAR, both the festivals were merged to unite the people of both the categories. Since then they have been celebrated as one grand festival during the tamil month CHITHIRAI.

MEENAKSHI KALYANAM

The Pandya king Malayadhwaja Pandian and queen Kanchana Malai,wasn't bessed with a child for a long time, so they performed special poojas and offered his prayers to God, to get a child who was the avatar of Devi Shakthi. The baby girl was named MEENAKSHI. She was born with the blessing that lord Shiva himself would come to marry her at the right age. Meenakshi was crowned as the Queen of the Pandya kingdom .When Meenakshi confronted Shiva in the battlefield at Kailash, she realized that she was an avatar of Shakti. As promised, Lord Shiva, along with all the devas and rishis, came to Madurai in the name of SUNDARESHWARAR. Lord Shiva married Lady Meenakshi and ruled the Pandya kingdom under the name Sundara Pandyan.

ALAGAR THIRUVIZHA

Once a rishi named Mandooka was bathing in the holy waters of Alagar hills. Rishi did not notice the arrival of Maharishi DURVASA. Rishi Durvasa took it as an insult and cursed Mandooka to become a Frog and live in the river VAIGAI. When Mandooka pleaded for mercy, Durvasa advised him to go to vaigai and pray to LORD ALAGAR(Vishnu) to be released from the curse. Lord Alagar was pleased by the prayers of rishi Mandooka and he himself came to the river to lift the curse off Mandooka. Later as Rishi Mandooka wished to witness his ten avatars, lord appeared in ten Avatars in front of him and blessed him. The Alagar festival is celebrated to remember this event.