Lord Shiva, the creator, preserver and destroyer of the entire universe is basically the part of two bodies as Rudra and Parvati. When the Sati died in the Yaga of her father Daksha, then Rudra perform the most energetic dance of destruction - TANDAVA. Everyone is fear about Lord Shiva. Then he send Veer Bhadra to kill Daksha and said those who came in between then kill him too. Then he killed whole army of Daksha but Narayan is the biggest devotee of Lord Shiva and Lord Shiva loves Narayan as devotee Veer Bhadra stop there and said I can't kill you, you are lovable of My Lord Shiva. Then Vishnu also said, "even I can't kill you". So Narayan tied Veer Bhadra with magical powers and Vishnu went away. Then Lord Shiva helps Veer Bhadra and released him, then Veer Bhadra killed Daksha, but before death he said that he trust Lord Shiva and said OM NAMAH SHIVAY, so when Lord Shiva come to take Sati's body then he give Daksha a new life but his head is buried into ashes in Yaga, so Mahadev gave him goat head. After that Lord Shiva takes Sati's body and left away Daksha Kingdom and went in the universe. Lord Shiva is crying for Sati. But no one is there to help as Gayatri Maa only decided to leave that body. But, because of this Demon Tarkashur decided to take three loks. He started killing the earth's people. Seeing this Narayan, Bhrama and all Devta are worried about it. Because only Shiva's child can only kill Tarkashur, but Shiva is hurted inside and taking body of Sati and roaming whole universe. So all Devta ask Vishnu to do something, but he said there is only one way, but it is very difficult. If Shiva get to know about it then he will destroy everthing. Then all devta requested and said but we have to take the risk as innocent people are killing. So Vishnu takes the risk and by his Sudarshan Chakra he cut down the Sati's body into 51 pieces. And all pieces are fallen down on Earth. Shiva get on the earth again. After that, he is seeing Sati here and there he didn't see any path, then Gayatri Maa came infront of him and said you have to make the pieces into Shakti Peeth, then only I will have a new born on this earth and marry again. So Lord Shiva established all Shakti Peeth around the world, but he still don't came up from feelings of Sati so he went in Amarnath cave and take Samadhi. After few days a girl born in the royal family of Himavan King named Him Naresh. He name that girl Parvati. Parvati is attacked by Tarkashur as he afraid of her death by Shiva and Shakti's boy. That's why Rishi Dadhichi requested that Tarkashur is not able to attack on his Ashram so please came to our ashram and live until Parvati grown up. Then after some years Parvati went to her Castle and there she realized that Shiva is only her husband, one night Parvati in night sleep went infront of the cave where Lord Shiva is in Samadhi after that she fainted, then her father Him Naresh search her around and found her. But before him, Lord Vishnu arrive and said you are my devotee and so I want to give you a job that your daughter is to marry Lord Shiva only, because Parvati is only the AdiShakti. So Him Naresh promised Vishnu that he will do every possible way to get Parvati marry to Lord Shiva. But her mother is against of this marriage and took promise that Parvati is only marry according to her wish and Parvati promise to her mother. After that she tried many things, so Parvati forget Shiva. But Shiva and Shakti are one only, how they can be seprated. So in one incident her mother realized that Parvati is right and allow her to marry Shiva. But Shiva is in Samadhi, so Parvati tried many thing. Once she done full bridal makeup and dance against Lord Shiva to wake him up from Samadhi. Lord Indra by taking permission from Lord Vishnu send Kama Dev and his wifi Rati in front of Lord Shiva and said that do evey possible thing they can do to wake up Lord Shiva from Samadhi so when Parvati dancing then Kamadev fire a arrow of Love on Lord Shiva but as we know without Shiva's permission no one can touch him, so he waked up from Samadhi and destory Kama Dev and Insult Parvati by saying that he don't know any Parvati. Then by this incident she thinks - "Is Lord Shiva also Loves him? Is he will accept her?" So to answer these question Vishnu send Narad Muni to help Parvati. Then Narad Muni said - "A human body have 16 Asudhi, and you have to remove them." He also gave the direction, said that this is the month of Savan, and Savan is most attractive month to Lord Shiva, and in Savan she have to fast for 16 Mondays. As this is the reason, why Indian women do fast of Lord Shiva, so that she will get good husband as they want. So Parvati went to remove 16 ashudi's in the caves of Amarnath, where Shiva takes the Samadhi. She done all possible way so that Mahadev accept him. After her devotion and love Lord Shiva came in front of him and said Yes I will marry you. But this tim Parvati said, No I have done my devotion to acquire you, now its your turn to acquire me. You have to come at my home and ask my parents to marry her. But as he is Lord Shiva, and he only gave thing and never asks. So all devta and Nandi and Bhoot Pret and gan request that do something that you don't have to ask anything and also he can fulfill Parvati's wish. So he went in Him Naresh Castle and perform Narayan Dasavtar Drama and seeing this her mother is so happy and ask him (Lord Shiva in face of Drama employee) to ask for any gift. Then he said he want to marry her daughter Parvati. Parvati's mother is so angry and tell him to go outside from her castle. But as Parvati know who is him so he told her father that the person who is performing the Drama is no one, but only Lord Shiva who came to ask for my hand for the marriage. So Him Naresh told her wife Menavati that he is no one but only Mahadev. So she is in fear that, she insult Mahadev and she agree for marriage. Then their marriage was solemnized a day before Amavasya in the month of Phalgun. This day of union of God Shiva and Parvati is celebrated as Mahashivratri every year.
JAI SHREE MAHAKAL