Political event
The Sindarin and Khuzdul have vastly divergent world views and have always preferred to dwell in separate communities. Nevertheless, they lived in harmony for five millennia, a golden age known as The Codominium. Then, as after The Reckoning, each race possessed skills complementary to the other. The Sirion Scrolls describe trade and friendly intercourse between the two peoples but with the coming age of man, relations between the two elder peoples began to decline.