Come August, and towering mud idols of the Ganesha, the Elephant God, begin to fill the sidewalks of Mumbai. You then know that Ganesh Chaturthi is round the corner.

Ganesh Chaturthi is celebrated on the fourth day of the Hindu month of Bhadrapad.The legend behind the birth of Ganesha is perhaps the most fascinating in Indian mythology.

It is said that Goddess Parvati, before taking an elaborate bath, wanted someone to stand guard at the door.

Not finding anyone, she created the idol of a child from the sandalwood paste that she had applied on herself, and breathed life into it. She told the boy she had created not to let anyone in, and went to have her bath. When her husband, Lord Shiva came home, the child could not recognise him and refused to let him in. Shiva was furious, and severed the head of the child.

When she learnt that the child she had created was dead, Parvati was distraught and asked Shiva to revive him immediately. Shiva ordered his lieutenants to get the head of any creature that was sleeping with its head facing north. The servants returned with the head of an elephant. Shiva joined the elephant's head to the boy's body, and Parvati's child lived again.

The legend also says that Shiva made the boy the leader of his armies. Hence, the name Ganesha, meaning 'god of the army'.

Lord Ganesha is the god of learning, and bestows both worldly and spiritual success. He is Vighnaharta, or 'remover of obstacles'. Invariably, his blessings are sought before beginning any new venture. In fact, the first prayer is always to Ganesha even on a day sacred to other gods.

It is considered inauspicious to look at the moon on Ganesh Chaturthi. The story goes that the Moon laughed at Ganesha's gait. The humiliated Ganesha cursed it, saying that anyone who watched it on that day (chaturthi, or the fourth day of the moon) would face a false accusation.