"Heroes of Might and Magic IV is a turn-based strategy game developed by New World Computing and published by the 3DO Company for Microsoft Windows-based personal computers in 2002. A Macintosh port was subsequently developed by Contraband Entertainment and released by the 3DO Company. The fourth installment of the popular Heroes of Might and Magic franchise, it is the sequel to Heroes of Might and Magic III, and was the last to be developed by New World Computing.
Following the events of Heroes Chronicles: The Sword of Frost, Gelu, the leader of AvLee's Forest Guard and wielder of Armageddon's Blade, attacks Kilgor, the Barbarian King of Krewlod, in an attempt to claim and destroy the Sword of Frost. As foretold by a prophecy, when Armageddon's Blade and the Sword of Frost clash in battle, the result is a massive explosion (known as the Reckoning), which destroys the world of Enroth. Many of the inhabitants of the planet, however, manage to escape through mysterious portals that appear during the Reckoning which lead them to another world, called Axeoth - also the setting for Might and Magic IX. Included among the refugees are many of the heroes of previous installments of the series, and many return to their old ways shortly after arriving on their new home."
Source: Wikipedia, "Heroes_of_Might_and_Magic_IV," available under the CC-BY-SA License.