Things briefly mentioned in the novels that are explained in this book.

[RumHam]

The Wood Dancers, Cult of Starry Wisdom, and Unmasking of Uthero are all mentioned in passing with no explanation in the main series.

Finally the wise of both races prevailed, and the chiefs and heroes of the First Men met the greenseers and wood dancers amidst the weirwood groves of a small island in the great lake called Gods Eye.

As she made her way past the temples, she could hear the acolytes of the Cult of Starry Wisdom atop their scrying tower, singing to the evening stars. A wisp of scented smoke hung in the air, drawing her down the winding path to where the red priests had fired the great iron braziers outside the house of the Lord of Light.

If you would be one of us, you had best know who we are and how we came to be. Men may whisper of the Faceless Men of Braavos, but we are older than the Secret City. Before the Titan rose, before the Unmasking of Uthero, before the Founding, we were. We have flowered in Braavos amongst these northern fogs, but we first took root in Valyria

Just wondering if anyone noticed any more of these.

[RumHam]

This thread really took off.

Anyway I found another. The mysterious Horn of Herrock from Feast is explained in the Westerlands section:

A generation later, the Lannisters captured the town of Kayce when Herrock the Whoreson blew his great gold-banded horn and the town whores opened a postern gate to his men.

[Lord Varys]

We now know why exactly Septon Murmison sucked as Hand.

What we do not know - and what I really wanted to know - is who the hell Alyssa Arryn was, and how she lost husband and all her male kin? Was she a born Arryn, perhaps even a Queen Regnant of the Vale, or was she just some widow who had married into the family.

[Mithras]

I think Alyssa was a mythical figure like the Winged Knight. She was probably a much older First Men legend like the Winged Knight but since she was very popular, Andals adopted her.

[Lord Varys]

Yandel seems to believe that Alyssa was a historical figure rather than mythological. The fact that he gave us a very detailed account on the historical Ser Artys Arryn as well as a detailed history of the construction of the Eyrie under Artys' immediate successors, strongly suggests to me that Yandel had access to pretty detailed accounts (written by septons, of course, but still...) on the early history of the Arryn dynasty.

And nothing suggests that Alyssa Arryn was an ancestor of Ser Artys.

The Falcon Knight may be nothing but a fairy-tale character, created by singers in the Vale by using the usual tropes from the stories about the Age of Heroes.

As soon as the Andals had taken the Vale they became Westerosi, and especially the Arryns would have wanted to give their rule more legitimacy by creating the image they have been there since the dawn of time (or that they had also a legendary hero in the past, just as the houses of First Men descent). They would have renamed the Vale 'the Vale of Arryn' for pretty much the same reason.

[Khal Shaggydog]

I loved that whole Vale backstory, and then we get a mention of Dolorous Edd's ancient and huge ancester being a great warrior! Classic.

I do think the whole world book was a clever way to introduce new info, while at the same time reconciling some of the contradictory info that has been floated out in the past, like the Falcon Knight and Arys Arryn, etc. Lann the Clever, etc. It reminded me somewhat of how Larry David pulled of a Seinfeld reunion on Curb without really doing a Seinfeld reunion (except at the end). You use a somewhat reliable narrator to tell these backstories, but in a specifically unreliable situation (he couldnt very well tell certain truths about King Bob, or House Lannister when the book was addressed to Tommen), and was able to explain some of the bolder contradictions with simply unreliable historical accounts. And the Mushroom rumors, etc. Great work.

I would definitely have appreciated some more detail about the historical Starks, but what we got was pretty good. Shrouded in the mists of time.

[Mrs.Grumpy]

Reyne-Tarbeck Rebellion is explained in the world book, whereas we only had tidbits and their ultimate fate in the books.

[Disputatious]

"I do think the whole world book was a clever way to introduce new info, while at the same time reconciling some of the contradictory info that has been floated out in the past, like the Falcon Knight and Arys Arryn, etc. Lann the Clever, etc. "

New info, and a mess of new misinfo as well :) :), or so it would seem.

[RoamingRonin]

Did the books ever tells us why Bloodraven was sent to the Wall? The world book does.

[SpaceChampion]

and Unmasking of Uthero are all mentioned in passing with no explanation in the main series.

I'm not clear if you're saying the world book does or doesn't explain this. It does, actually. Uthero was a Sealord of Braavos who made a treaty with Valyria, announced the existence of Braavos to the world, and paid a financial settlement to all the Valyrians who had their ships stolen by the escaping slaves who ultimately founded Braavos, but of course refused to compensate those Valyrians for the monetary value of the escaped slaves.

[RumHam]

I'm not clear if you're saying the world book does or doesn't explain this. It does, actually. Uthero was a Sealord of Braavos who made a treaty with Valyria, announced the existence of Braavos to the world, and paid a financial settlement to all the Valyrians who had their ships stolen by the escaping slaves who ultimately founded Braavos, but of course refused to compensate those Valyrians for the monetary value of the escaped slaves.

Yeah I was saying it does, while the main series just mentions these things in passing with no explanation.

[ACVG]

It did give a semi explanation of why Aegon might abandon his mission to conquer Dorne despite having 2 remaining dragons.

If the note explained that Rhaenys was still alive...