1. The letter
Once upon a time, before the days of Discord and Nightmare Moon. There were a kingdom in the north. It was called "The Icy Kingdom" and were ruled by Prince Ice (Princess Celestias uncle) and his lovely wife, Princess Windy. The Prince and the princess had a child named Prince Blueblood.
The kingdom was beautiful. In the middle there was the palace and around it a big wall, made of ice and stones. The houses were cozy and warm with smoke coming up from the fireplaces. The streets decorated with little snowflakes and snow lamps. There were kids playing in the streets and life in every home. Everyone were happy, even though it was cold. There were the best guards to protect the kingdom. There were igloos and snowmen In front of the houses, with the children and babies. Yes the icy kingdom was truly amazing.
Then the catastrophe happened. A big cloud full of snow flew over the kingdom and dropped the snow. Everything drowned with snow. Prince Blueblood were so lucky to be in Canterlot when the catastrophe happened. In the icy kingdom nothing survived the snow. And slowly it began to sink down, so there were nothing to see. Celestia were at the time 16 and had just taken over Equestria, but she didn't know what to do! She didn't want every pony to think it was her fault. So she decided to cast a spell on every living thing, she was the only pony who knew about it.
Today nopony knows about the icy kingdom and nopony cares. Besides me....