Different Points of view in Fantasy

Heroes of Might and Magic IV in particular has several campaigns for different fractions with different characters dedicated to the building of a new life in a new world. World from which they came is also mentioned occasionally, it was destroyed by a cataclysm and the only way to escape death were the portals.

Also in the old very first WarCraft: Orcs and Humans you can play as orcs who just came to Azeroth via the Dark Portal (the same one through which many years later WoW players went into what was left out of orcs' homeworld to fight against Illidan in Outland) to launch an invasion against Stormwind (whch at the time was called Kingdom of Azeroth).