First Ice Age

The First Ice Age, as it was known by the time of the Second Ice Age, (TV: The Ice Warriors) was a period notable for its widespread glaciers. (TV: In the Forest of the Night) Neanderthals. (AUDIO: The Exxilons) and humans both lived during this Ice Age, as did Mammoths (TV: In the Forest of the Night)

History
During this time, an Ice Warrior craft from Mars crashed and buried itself. (TV: The Ice Warriors) The Dæmons visited Earth, and according to the Third Doctor, inspired cave paintings of powerful supernatural beings. They favoured humans over Neanderthals, causing the latter to die out. (TV: The Dæmons)

The First Doctor visited Earth during the Ice Age, where he encountered a monster. (COMIC: The Ice-Age Monster)

In Birmingham during the Ice Age, the Eleventh Doctor and Amy Pond saved a group of Neanderthals who were being experimented upon by aliens. (COMIC: Snow Globe)

Legacy
Thousands of years later came the Second Ice Age, circa 5000. (TV: The Ice Warriors, The Talons of Weng-Chiang)

Behind the scenes

 * In the real world this Ice Age was by no means the first, and is referring to the, which is the latest in a long line of "ice ages". Glacial periods are cyclical, and occurred consistently throughout the . Outside of that, an early hypothesised "ice age" in Earth's history was the.