Ethelred the Ever-Ready was a wizard who was famous for taking offence for no reason and casting curses at innocent bystanders. He ended up dying in prison.
The name Ethelred is composed from Old English elements æðele, meaning "noble", and ræd, meaning "counsel", being bombastic and common in the Royal House of Wessex.
King Ethelred II of England was known as the Unready after his death (from Old English Æþelræd Unræd). In that time, "unready" was probably understood pejorative as "evil counsel" (opposite to the name) or "bad plan"; the king was considered ill-advised or indecisive in his conflict with the Danes.