Modern Era

1000+

Around the year 1000 there was the assassination of the Last Great King, Leander Vestalis. There are many stories about what actually happened, but it seems after he died there was no real succession plan in place. Many factions could not agree on one and so the "kingdom" fell apart.   For many this was fine as it allowed regions to return to what they felt were their borders before he had united the civilized lands. It did create some instability, but there were plenty of factions which were ready to step in and take over.   Since then many regions have become more isolated and only concerned themselves with other regions for major issues, but usually avoiding any major alliances.  

Current Situation

  Many regions are settled in their ways and with no concern of who is in charge. As long as the economy is going and the monster attacks are abated they are satisfied to let things be. In other regions there are those who are seeking power. Various kingdoms and regions have found their own freedom and has seen to them finding their own way and setting the stage for various coups. It is a time of loose stability.

Summary

Long ago a king of crazy heritage (he had links to the human, orc, human, elf, dwarf, gnome, and even halfling heritages) came to power. With might, strategy, and prowess he brought many of the main civilizations to unity. He put down a calendar and the current gold standard. He was able to help standardize much of the trade routes still used today. Then he died. Since then many regions have become more isolated and only concerned themselves with other regions for major issues but usually avoided any major alliances.

Historical Basis

This would be the most "reliable" of known history, and it is still full of myths, legends, and mistatements of facts. Because there are many "factions" which have long controlled the narrative it can make it difficult for most lay people to know how to separate the fact from the fiction.