Edward Williams (more widely known by his pen-name, Iolo Morganwg) was a poet, writer and antiquarian. He had strong connections with the London-Welsh societies of the late eighteenth century, and was particularly affected by the cultural and antiquarian developments of that period. In 1792 Iolo Morganwg held the first meeting of the Gorsedd of the Bards of the Isle of Britain in London. During the occasion he introduced a form of druidism, later discovered to have no true historical root. Morganwg is arguably the most controversial writer and poet Wales has even known. He did not live to see his volume ‘Cyfrinach Beirdd Ynys Prydain’ in printed form. It was published in 1829, three years after his death. This truly unique thesis on the origins of the poetic art of Wales demonstrates Iolo Morganwg’s firm grasp on the subject. However, both his broad knowledge and extraordinary imagination are evident in ‘Cyfrinach Beirdd Ynys Prydain’. In this volume, he rejected the pre-standardised poetic forms introduced by Dafydd ab Edmwnd in the fifteenth century and proposed in their place old strict measures as well as newly formed ones. Morganwg supported his propositions with falsified examples, derived from ancient Glamorgan poets, which also served as proof of the literary excellence and authority of his home county.