I've heard it said that Roman empire finally ended in 1283 with the Norman conquest of Gwynedd, since that would mark the end of the period of uninterrupted Rom

I've heard it said that Roman empire finally ended in 1283 with the Norman conquest of Gwynedd, since that would mark the end of the period of uninterrupted Roman rule (assuming one believes that the rule of the Welsh princes descended from Roman rule in Britain nearly a millennium earlier). The reality is that the decline and fall of the Roman Empire wasn't a sharply defined event and more of a process that took an awfully long time. The idea that lead poisoning contributed to that process is an interesting one but I'm not sure that the article answers any questions about that.