One day Parvathi, wife of Lord Siva made a boy with turmeric & breathed life into it. She then asked the boy to guard the door till she took her bath. The boy was instructed not to allow any one to enter. When Siva came and tried to open the door, the boy objected to it. In a fit of anger Siva severed the boy’s head with his Trishul. When Parvathi came to know what had happened to the boy she began to weep. Seeing this Siva’s heart melted and he promised to put back life into the boy. After a massive search Siva’s disciples could find the head of an elephant to fix on the boy’s body. From then on he was called Gajanan, the elephant-headed boy. From this day is celebrated as birth of Lord Ganesha. The idol of the Lord is worshipped for 10 days and on the eleventh day it is immersed in river or sea amidst a huge procession.