Indeed the song is political, and thanks to Robert Graves for the key, I can tell ye what in truth it is about, 'though but a twisted outline remains in the modern versions.

It takes place during the long and grim patriarchal supplantation of the Old, matriarchal Order.

A would-be king and his hangers-on enter an unconverted territory. Anglesey was one of the holdouts, so the title is appropriate, 'though the drama played out in many places over a thousand years or more.

They enter the Grove and announce that the Mother is dead and there is now a King in the land. The Priestess softly says that She is not dead at all, that perhaps the King might be interested in a royal marriage? And that his meanest lord might start the festivity by dancing with her youngest daughter.

Visions of conquest sweetened with rape swirling like smoke in his head, the King assents and the dance begins.

The young priestess successively dances the lords into muck-sweat and heart-failure, light as the foam on the broken sea. Possibly before they are all down, the remnant see the ruse and rush in with drawn swords. But if the magic is still strrong enough, they are whirled to their doom, as well.

Once his thanes are all down, the High Priestess probably personally invites the King to his last dance.

Of course, eventually kings learned as Odysseus did to stop their ears to the Sirens' songs,and the world changed.