There is a similar (made-up Victorian) prophecy concerning London Stone. When it was temporarily removed from its site on Cannon Street during construction work, I remember thinking that couldn’t be a good sign, and sure enough: Brexit.
It has since been restored, and the new building has a nicer alcove for it, but obviously the teleological aftershocks are ongoing. Hopefully the Corporation of London will tighten up their mystickal safety protocols in future.
Fun Fact: By law, the birds are only allowed to have one mouth each because The Criminal Justice and Public Order Act of 1994 outlawed raven to repetitive beaks.
The three concealments and disclosures of the Isle of Britain. The first was the head of Bran the Blessed, the son of Llyr, that Owain the son of Ambrosius had concealed in the white hill in London; and while it remained in that state, no injury could happen to this Island… And Arthur revealed the head of Bran the Blessed, the son of Llyr, because he scorned to keep the Island but by his own might; and after these three disclosures, the invaders obtained the superiority over the Cambrian nation.
I shot the raven,
But I swear it was in self-defense
Oh no no
I shot the raven
But I didn’t shoot no albatross
I shot the raven
And they say that it is Britain’s loss