Kartikeya, the god of war, and generalissimo of the armies of the gods, though called the younger son of Siva and Parvati, according to most of the Puranic legends, is their son only in the sense that they formed him.
There once lived a demon named Tārika. This demon, who was King of Tripura, was ” exceedingly ambitious and oppressive.He forced Brahmā, by his penance and austerities, to promise him any boon that he should demand. Such merit was irresistible, and Indra and a host of demi-gods, alarmed lest their sovereignty should be usurped through the potency of this penance, resorted to Brahmā for consolation. Brahmā, however, said that, although he could not resist such austerities, he would, after rewarding them by granting the boon demanded, devise a method of rendering it ultimately inoffensive to them.
The demand by Tārika was that he should be unrivalled in strength and that no hand should slay him but that of a son of Mahādeva. He now became so arrogant that Indra was forced to yield to him the white eight-headed horse Ukhisrava; Kuvera gave up his thousand sea-horses; the Rishis were compelled to resign the cow Kāmdhenu, that yielded everything that could be wished. The Sun in dread gave no heat, and the Moon in terror remained always at full. The Winds blew as he dictated, and, in short, he usurped the entire management of the universe.
They prayed for years to Lord Shiva to intervene in the matter and save them.
Nārada prophesied the marriage whence should arise the deliverer of the world; but at first Mahādeva could not be influenced with the passion of love. Indra persuaded Kama to lie in ambush, and contrived that Pārvati should be seen by Siva while engaged in the amiable and graceful act of gathering flowers, wherewith to decorate his image. Kāma, accompanied by his wife Rati (Desire), and his bosom friend Vasantu (the Spring), took his aim, and launched an arrow at Mahādeva, who, enraged at the attempt (to interrupt his devotion), reduced Kāma to ashes by a beam of fire that issued from his third eye. At length, however, by ardent devotion and austerities, Pārvati propitiated Siva, and the deity consented to espouse his persevering devotee.
For some time after their marriage, as there was no child born to them, the distressed and disappointed deities who had been anxiously expecting a deliverer, renewed their lamentations and complaints.
Finally, the Lord’s mercy gave way and he decided to give rise to a new manifestation of his power to kill the demons. From Lord Shiva’s eyes came out six sparks. Since they were too hot to be borne by any other element in the creation, the task was given to Agni to carry them forward.
Agni arrived in the presence of Mahādeva, having been deputed to express the desires of the other gods, that he would provide them with a son, who should destroy Tārika. Siva emitted sparks of fire from his eyes, Agni, Unable to carry it further, he let it fall into the lake Saravana, became six infants, who were nursed by the wives of the Rishis, who are seen in the sky as the Pleiades. When Pārvati saw these children, she was transported with their beauty, and embraced all of them together so forcibly that their six bodies became one; while their six heads and twelve arms remained.”
“It happened that six daughters (the Pleiades) of as many Rajas, coming to bathe, saw the boy, and each called him her son; and, offering the breast, the child assumed to himself six mouths, and received nurture from each; whence he is called Sasthimātriya (having six mothers). But in fact the child had no mother, for he came from his father alone. In course of time a conflict ensued between Kartikeya and Tārika, in which the demon was slain.”