Here is the poem by Taliesin, which dates from about the 6th-century, but there are scholars who dispute the date of the MS. Sir John Rhys came forth with the best argument in the early 20th-century with the claim that the earliest MS dates from the 9th-century.

Praise to the Lord supreme ruler of the high region,
Who hath extended his dominion to the shore of the world,
Complete was the prison of Gwair in Caer Sidi.

Through the permission of Pwyll and Pryderi No one before him went to it;
A heavy blue chain firmly held the youth.
And for the spoils of Annwn gloomily he sings,
And till doom shall he continue his lay.

Thrice the fullness of Pridwen we went into it,
Except seven, none returned from Caer Sidi.

Am I not a candidate for fame to be heard in the song?.
In Caer Pedryvan four times revolving!/,

In it will be my first word from the Cauldron when it empresses;.

By the breath of nine damsels it is gently warmed.

Is it not the cauldron of the chief of Annwn in its fashion?

With a ridge round its edge of pearls!.

It will not boil the food of a coward not sworn,
A sword bright flashing to him will be brought,
And left in the hand of Llemynawg,
And before the portals of hell, the horns of light shall be burning
And when we went with Arthur in his splendid laborers
Except seven, none returned from Caer Vediwid, (the enclosure of the perfect ones)

Am I not a candidate for fame, to be heard in the song,
In the quadrangular enclosure, in the island of the strong door,
Where the twilight and the jet of night moved together,
Bright wine was the beverage of the host,
There times the fulness of Prywen, we went to sea,
Except seven, none returned from Caer Rigor ( the enclosure of the royal party).

I will not have merit, with the multitude in relating the hero`s deeds,
Beyond Caer Wydr they beheld not the prowess with Arthur,
Three times twenty hundred men stood on the wall,
It was difficult to converse with their sentinel.

Three times the fulness of Prydwen, we went with Arthur,
Except seven, none returned, from Caer Colur ( the gloomy enclosure)


I will not have merit with the multitude with trailing shields,
They know not on what day, or who caused it,
Nor what hour in the splendid day Cwy was born,
Nor who prevented him from going to the members of the Dvwy.

They know not the bridled ox, with his thick headband,
And seven score knobs in the collar,
And when we went with Arthur of mournful memory,
Except seven, none returned from Caer Vandwy ( enclosure of resting on the height)


I will not have merit from men of drooping courage,
They will know not what day the chief was caused,
Nor what hour in the splendid day the owner was born;
What animal they keep of the silver head.
When we went with Arthur of the mournful contention,
Except seven, none returned from Caer Ochren ( enclosure of the shelving side)

Monks pack together like dogs in a choir,
From their meetings with their witches;
Is their but one course to the wind, one to the water of the sea,
Is there but one spark to the fire of the unbounded tumult?
Monks pack together like wolves,
From shier meetings with their witches,
They know not when the twilight and the dawn divide,
Nor what the course of the wind, nor who agitates it,
In what place it dies or what region it roars,
The grave of the saint is vanishing from the foot of the altar.

Also, if anyone wants a real treat, you can actually listen to the poem in Welsh at this site here. Preddiu Annwn I think it is neat because one can get the tempo for the poem as it is in close to the original language.

Enjoy all!