Grails mysteries

I shall have a son
Out of Cornwall shall he come
That shall be a wild boar
Bristled with steel
He shall be a man most brave and
Noble in thought

Thou shall kneel for him
For every man shall humble in front of our lord
I stood upon the sand of the sea
And the great wind told me to carry on
He shall once know the secret of Holy Grail

And so was the coronation made
And there was he
Sworn unto his lords and the commons
To be true king