In the early days of the construction of Sildëyuir, Gamogan was an outspoken opponent of the plan, claiming that it would strain those relations that had already been made with the humans and the existing allies of Yuireshanyaar.
He decided to contact the neighboring nations and tell them of the construction of Sildëyuir. Unfortunately, this information was used by a human tribe, who had falsely claimed to want an allegiance with the star elves, to attack an enclave, slaughtering all of its inhabitants and stealing tens of thousands of gold pieces worth of materials that were needed to create the portals to Sildëyuir.
Gamogan, despite his good intentions, was banished from star elf lands and remembered by all as a vile traitor. His example was used by later star elves to always look to security before trusting in the good-will of strangers, which for the most part led to the star elves' insular standpoint.