Giraldus Cambrensis (Gerald of Wales) wrote in his Description of Wales (1194) about people called 'Awenyddion' as follows:

There are certain persons in Cambria, whom you will find nowhere else, called Awenyddion, or people inspired; when consulted upon any doubtful event, they roar out violently, are rendered beside themselves,and become, as it were, possessed by a spirit. They do not deliver the answer to what is required in a connected manner; but the person who skilfully observes them, will find, after many preambles, and many nugatory and incoherent, though ornamented speeches, the desired explanation conveyed in some turn of a word: they are then roused from their ecstasy, as from a deep sleep, and, as it were, by violence compelled to return to their proper senses. After having answered the questions, they do not recover till violently shaken by other people; nor can they remember the replies they have given. If consulted a second or third time upon the same point, they will make use of expressions totally different; perhaps they speak by the means of fanatic and ignorant spirits. These gifts are usually conferred upon them in dreams: some seem to have sweet milk or honey poured on their lips; others fancy that a written schedule is applied to their mouths and on awaking they publicly declare that they have received this gift.

(Chapter XVI: Concerning the soothsayers of this nation, and persons as it were possessed)