Lord shiva is the greatest of gods, He is called Mahadev -Maha means great among the deities.There is a story to show how he loved his wife Parvati.
Once there was a holy sacrifice at the residence of his father in law(Dakhsa) but since he did not like Shiva he did not invite him. His wife Parvati despite her husbands advice that it is not proper for her to go to her fathers house uninvited, She goes there.There she finds that her father is insulting her husband by not giving offerings in his name she jumps in the fire and dies,Shiva when learns it goes there Kills all the men there and carries the dead body of her wife in a vow to destruct the whole world Gods fear his anger and they with their power break the corpse into !2 pieces and each fell on earth.
Each place where the body parts fell becamed a shrine
every year aday is afestival called Siva ratri (night of lord Shiva) when virgns pray lord Shiva to grant them and a goodand devoted husband like Siva
and even today these twelve shrines are there in India and are calleed Dwadash (Twelve)Jyotirlinga (Jyoti-light and Linga-Phallus)