Instruction:
What was the Long Night?

Response:
According to legends in Westeros, the Long Night was a darkness that fell over the known world and the Westeroi were subjected to not only a generation-long winter, but also the terror and destruction brought on by the Others. A similar telling comes from across the sea where the people of Essos experienced a winter that froze their waters and the Yi Ti described a generation where none saw the sun.