From an early date Williams was concerned with preserving and maintaining the literary and cultural traditions of Wales. He produced a large number of manuscripts as evidence for his claims that ancient Druidic tradition had survived the Roman conquest, the conversion of the populace to Christianity, the persecution of bards under King Edward I, and other adversities. His forgeries develop an elaborate mystical philosophy, which he claimed as a direct continuation of ancient Druidic practice. Williams's reportedly heavy use of laudanum may have been a contributing factor.