The Background
The Naandi ceremony is a ritual in the Tamil Iyengar wedding that is performed to please the Naandi Devtas. Referred to as Pitrus, Naandi Devtas are the ancestors who have departed. It is believed that the Pitrus lay the foundation for the creation of the physical body. Therefore, it is important to pay gratitude to the ones who created us. Not only at weddings, even during all auspicious events they are the first ones to be thanked and prayed to. 

In addition to this, there is also a belief that this ceremony is performed to offer prayers to all the 33 Vedic Deities who represent splendour, knowledge, strength, truth and wealth. They are invoked to subdue evil forces and make nature benevolent. The hymns chanted during this ceremony describes the distinctive traits and individual characteristics of each Vedic God. 

The Procedure
During the beginning of this Tamil Brahmin Iyengar pre-wedding ritual, a Pipal tree along with its leaves is planted at the center of the altar and five sumangalis (married women whose husbands are still alive) come forward and wash the tree with milk. Once this worship is completed, a saree is gifted to the bride and a dhoti to the groom once they are anointed with sandal paste, turmeric powder and vermilion(kumkum). The presumption is that all the Vedic deities and ancestors arrive and witness the wedding and bless the couple for a peaceful and prosperous life together.