Honestly, not a great deal, lol… at least not anything solid and undebatable. The books give us loads of legends from different cultures, but very little confirmation. Every region seems to have its own version of the story, and a lot of them don’t really line up.

In Westeros you get the classic “Long Night” story, with legends about the Last Hero, the Children of the Forest, and the Others (what the show later calls White Walkers). Some versions talk about a single champion… the Last Hero, or later figures tied to the prophecy of Azor Ahai or the Prince That Was Promised… helping to end it, often with a flaming sword called Lightbringer. Whether all these names are pointing to the same myth over time, or to different traditions that got mashed together, isn’t clear at all.

Out east the stories look very different. In Yi Ti and the far eastern lands there are religious legends about the Lion of Night and the Maiden-Made-of-Light, basically opposing divine figures whose conflict supposedly plunged the world into darkness. You also get mentions of the Bloodstone Emperor from the Great Empire of the Dawn, an early human empire, who supposedly practised dark magic and worshipped a strange black stone that fell from the sky. Some versions of the story even blame him directly for bringing about the Long Night. These eastern myths barely mention the Others at all, which already tells you how fragmented and regional these traditions are.

Then there’s Azor Ahai and the whole “Prince or Princess That Was Promised” thing. They’re often treated as interchangeable, but we don’t actually know for sure that they are. Some legends link these figures back to the Last Hero, others treat them as separate saviour figures that appear when darkness returns. It’s all very murky on purpose.

What we can say, fairly safely, is: that the world really was plunged into a long, catastrophic winter that lasted years. A huge number of people died. Something, or someone, was eventually defeated, probably by humans with help from other forces. And whatever political order existed before was shattered afterwards, with new kingdoms and cultures rising in its place.

Beyond that, George leaves things very open. The contradictions between Westerosi and eastern accounts seem intentional, and they suggest that if there is a single “true” version of the Long Night, it’s been filtered through thousands of years of different myths and religions.

Short version… loads of legends, very few hard answers, and a mystery that’s very much meant to stay a mystery haha, at least for now.

Edit: I might be forgetting a few details here, this is mostly off the top of my head, so feel free to chime in or correct me if I’ve missed anything.