Phekar

The Phekars were a warmongering culture that founded an empire and ruled vast lands before their fall. Their brutal conquering methods left scars all throughout their old dominion, as they forced their subjugated vassals to fight equally brutal in foreign lands. If any group of soldiers held back, their families at home would pay the price.
Former battlefields and ruins of former capitals still remind of these brutal wars, with descendents often refusing to forgive the people forced to perform these deeds. As such, there are still many tensions between the former vassal countries. This has led to more warfare and further grudges, leaving behind a legacy of war and death. Even the old country was simply dragged into old grudges that make little sense, yet have led to the brutality of destroying the water reservoir and flooding many towns.
But it wasn't just countries that faced the consequences of resisting the Phekars. Many other species, such as several Fae species, were conquered violently and have lost their faith in the ability to live peacefully near civilizations. Some, such as the Arboreals, were even wiped out in their entirety. Now these only live on in myths.
With this knowledge, it is hardly any relief that the Phekar Empire imploded into infighting during a succession war, which then left space for a massive uprising that showed exactly what lessons had been learned.
There are some positive influences left behind to the centuries-long rule of the Phekar Empire. Countries still use comparable coins and speak near-identical languages, which makes life easier for merchants and Scouts. Many old roads still are maintained well, which can be abused for warfare but also make it easier to travel far and wide. But these benefits hardly are worth it compared to the trauma so many still have yet to overcome.