Before reaching the surface, the dwarves encountered the goblins. A few of these encounters were bloody, but these escalations were short lived. The goblins took note of the superior arms and armor of the dwarves and sued for peace accompanied with trade agreements. The dwarves, seeing that they were getting a great deal (after all the goblins were completely ignorant that the dwarves were outcasts of their deeper brethren, who forged incredible, quality arms and armors in Rootstone) accepted. Of course, the dwarves had never tasted goblin cuisine, the foodstuffs received from the goblins were harsh to the palette. To this day, both races still wonder who got the upper hand in those trade agreements.
The goblins warned the dwarves that some of their tunneling operations would eventually run afoul of the elven mountain kingdoms. The dwarves, curious and stubborn (it also might be noted that they were feeling confident after their cessation of hostilities with the goblins) ignored the goblins warnings and continued upwards through the earth, yearning to breach to the surface.
The dwarves tunneled straight into the mountain citadels of the elves. The elves, viewing this a violation of their sovereignty, insisted that the dwarves either turn around and go back the way they came or become vassals of the elves. The dwarves, affronted by what they viewed as elven obstinancy, began a brawl that would turn into a series of wars that would last a century. It should be noted that this is where the saying, “Time to beat the elf out of you,” originated. But I digress. Apologies. Both races became weary of fighting, treaties were signed, and the dwarves collapsed the tunnels that wormed into elvish cities.
The dwarves eventually became accustomed to the sunlight. During this time, some dwarves left their brothers to become citizens of the elven kingdoms, but the majority left the elves alone and settled elsewhere in the surrounding mountains. 500 years later after the last exodus from the Eadh-Deash, several surface dwarves decided to send expeditions back to Rootstone to see how their deeper kin fared.
Those expeditions that made it back to the deep dwarf cities created quite a stir. The deep dwarfs were shocked to see their former brethren with darker, sun touched skin, using torches and lanterns to help guide their way through Rootstone. The majority of deep dwarf cities abolished Eadh-Deash, instead sending their dissidents and failed Echoes of Earth candidates to the surface dwarves. Trade was soon established with the surface dwarves. Rootstone caravans began making regular routes to the mountain and highland realms. Many deep dwarf cities decided to give their surface kin a measure of respect and they're not shunned as they were when under the laws of the Eadh-Deash.
Though they trade and interact with their sun loving kin, many deep dwarves hold that the surface dwarves are the weaker subrace. The sunlit lands have softened their minds and bodies, corrupting their respect for the deep dwarf laws and traditions. Add to the fact these were individuals who descended from dwarves who failed Gharas-akhdrat, the disdain only deepens. The more hospitable cities in Rootstone allow a surface dwarf to stay as a 'guest' in their city for a maximum of a week unless special circumstances merit otherwise. Despite this prejudice, many deep dwarves appreciate the wood from the forests above and the tasty foodstuffs that come with the caravans (which by the way, are not goblin, or so I've been told).