aim was to assert the Welshness of South Wales, particularly his home region of Glamorgan, against the prevalent idea that North Wales represented the purest survival of Welsh traditions. The metaphysics elucidated in his forgeries and other works proposed a theory of concentric "rings of existence", proceeding outward from Annwn (the Otherworld) through Abred and Ceugant to Gwynfyd (purity or Heaven). Outside his shop in Cowbridge was a sign saying his sugar was from plantations that employed no slaves. However, he contested a will in order to receive a legacy from one of his three brothers, all of whose plantations in Jamaica used slave labour. By 1799 he had become a Unitarian and a leading spirit when a Unitarian Association was formed in South Wales in 1802. It was he who drew up its Rheolau a Threfniadau (Rules and Procedures), published in 1803. Bardic alphabet Iolo Morganwg developed his own runic system based on an ancient druid alphabet system, in Welsh Coelbren y Beirdd ("the Bardic Alphabet"). It was said to be the alphabetic system of the ancient druids. It consisted of 20 main letters, and 20 others "to represent elongated vowels and mutations." These symbols were to be represented in a wooden frame, known as peithynen. Exposure Towards the end of the 19th century, the grammarian Sir John Morris-Jones was involved in exposing Iolo as a forger, which led to the bard being labelled a charlatan. Morris-Jones called Iolo "hateful" and said it would be an age "before our history and literature are clean of the traces of his dirty fingers." After the First World War, the scholar Griffith John Williams (1892–1963) was the first to make a full study of Iolo's work, consulting original documents donated to the National Library of Wales by Iolo's descendants in 1917. Williams aimed to find out exactly how much of Iolo's output was based on imagination rather than fact. He established that the poems Iolo attributed to Dafydd ap Gwilym were forgeries. His researches led him to become a defender of Iolo's reputation as well as a critic. It has been suggested that some of Iolo's claims were supported by oral tradition: recent research has revealed that the tale of Ieuan Gethin, a soldier in the Glyndŵr revolt, might have basis in fact. Legacy Such was the extent of his forgery that, even into the 21st century, some of his tampered versions