Elves, like the dwarves, have always had a slight prescence here but unlike the dwarves they never settled. As humans came into the lands and started exploiting the Northern woods they began to rub up against some of the Southern elf clans. Eventually they were able to work out a compromise and open up some trade routes. As the great goblin war began to seep into the valley the elf nations as a whole were slow in joining the fight. When Thrun fell that was just too close for comfort and they rushed to the Republics aid. In the years after the Tempest the merchantile elves managed very successfully to move the blame off of their people (who were known to of summoned it) onto the practice of magic. Now elves are a significant minority in the towns of the modern Republic.
Before the badlands were orcish there were some elven clans in the northern part of the region and they were there all the way upto the occupation of the Flareheart Mts.
This is where elfkind has always been strong and at their most diverse. The history of the fiefdoms is of fuedal little countries scrapping with each other constantly with limited success. Things changed when the local leaders grouped together and decided as a single entity to enter the great goblin war (and later on the same group and one or two others invoked the tempest).