Let Me Tell You a Story:
There was a battle for Heaven between the demon Spirits and the good Spirits, the Danavas, which the Danavas won. The Demon Spirits then took birth into the world to take over the Earth. The Lord Shiva thought it was time for the world’s end, i.e. cosmic dissolution-pralaya, but the Lord of Creation took the avatara of Lord Krishna, and along with the five Pandava princes sired by the Danavas, he attempted to defeat the Kauravas and Rakshasa spirits.
The World lived off of the avatara of the Lord Krishna for a long time; for a time everything was a wonder and a miracle for his followers, but Man was destined to perish for being wanton and evil.
In 1250 B.C.E. the end was ordained when to gain advantage people took to worshipping a form of the deva Ganesha, and then its fate sealed when it worshipped the form of Kali.
Eventually, the Nayanars in India were conquered by the British by the 17th century and people stopped worshipping the Lord altogether.
Thus from the time 1680 A.D. on, the World was lost to the Demon Spirits, and the end of the world became a certainty.