Today is Kartik Poornima, a religious observance marking Lord Shiva’s mighty deed as Tripurantaka (“Destroyer of the Three Cities”), which brought to a decisive and victorious end one of the Gods’ wars against the Asuras. It’s probably the second most significant Shaivite observance after MahaShivRatri (“The Great Night of Shiva”), which occurs in February/March.
The story behind this event is as follows. Following the death of Tarakasura at the hands of Kartikeya (Shiva’s son); the three sons of Tarakasura – demon princes in their own right – attempted to petition Lord Brahma for a boon. They asked for immortality; although were informed that true inviolate protection from the powers of death was beyond even Brahma’s abilities to bestow upon them (in our metaphysics, almost nothing is entirely everlasting). Instead, the three Asuras therefore asked for a sort of conditional immortality – the bestowment of three impregnable fortresses (the Tri-purs earlier mentioned), which would only be destructible if they were all hit simultaneously by a single arrow – a feat rendered even more improbable by the fact that all three fortresses were in constant motion and would only be coterminous but once a millenium for a few moments at a time. Provided that these three strongholds remained, the three Asura would still live. But should they be destroyed, then their fate would lie along with them.
Now, there, the story might have ended. Except that despite the tellings of some versions of the legend that the Demons were worshippers of Lord Shiva (a not entirely uncommon phenomenon – consider & compare Ravana), left to their own devices inside their fortresses, their actions and thoughts turned to impiety. Worse, the cavernous spaces within provided ideal rallying-points and marshalling-grounds for demon armies – who, due to the highly mobile nature of the fortresses in question, were able to use them as staging-points to harry and raid forces loyal to the Gods right across our plane of existence.
Something had to be done. But The Gods, in all Their Might, were not able to assail the cities.
Desperate, they (on the reputed advice of Brahma) petitioned Mahadev for His Almighty Assistance in putting an end to the evils and marauding of the Asuras and their cities.
Lord Shiva made ready for War – but was aware that no ordinary arrow and mechanism of its release would do. So, a mechanism of war unique in the history of the universe was designed that would utilize the very forces and nature of creation itself to construct a chariot, arrow and bow for Mahadev to use in the Tripuras’ hoped-for and heralded destruction.
To give an idea of the scale of the warmachine, the Sun and Moon were used to provide the wheels of Lord Shiva’s War-Chariot, assisted in the rest of the formation by various Gods; while Mt. Meru (the axis mundi of the very universe itself) was used to form the Bow. Meanwhile, the Arrow was comprised of the combined forces & essences of parts the Hindu Pantheon of Gods working together in concert (so, Lord Vayu, the Wind God, was in the feathers of the arrow; Lord Vishnu, the stability, was in the shaft; and Lord Agni, the Lord of Fire, was the warhead).
The chariot sped towards the appointed spot and the precise time at which the mighty missile would be unleashed, and all awaited with baited breath for the moment of the cities’ unraveling.
But then, something unexpected happened – for Mahadev is the master of working in subtle ways towards the grander scheme which only He knows …
Whether due to a rejection of The Gods’ hubris (as some tellings of the myth have the Devas starting to take credit for the Tripuras’ destruction even before it had yet begun), or due to some other even more inscrutable causation … Mahadev did not fire His Arrow.
Instead, He simply Smiled. And the Three Cities of the Asuras began to burn.
The Gods were astounded. By the merest and simplest of changes in His facial expression, Mahadev had accomplished what They in the rest of the Pantheon had spent an aeon unable to do.
However, Lord Brahma then interceded, and beseeched Lord Shiva to fire the arrow anyway – His logic being that if word got out that The Gods had been effectively totally powerless in this situation, rather than contributing to the mighty victory, it might do irrevocable reputational damage to Them and Their Cause on into the future.
Mahadev thus relented, and fired the arrow anyway; although also dispatched His Seneschal, Nandi, to aid in the evacuation of the demon-architect Mayasura – who had remained faithful to Mahadev.
The Story of Tripurantaka thus demonstrates a number of important truths relevant to the Shaivite creed – namely, that Lord Shiva is the supreme power, existing beyond even Lord Brahma and the combined might of the Hindu Pantheon; that He will often act in seemingly inscrutable ways (where small things in fact have great and significant outcomes); and that His Devotees, should they remain pious, shall be provided for.