Aethelred, one of the most hated kings of England, inherited the throne when he was ten years old. His name comes from the Anglo Saxon name for him, "Unraed," which means "evil-counseled," or "uncounseled," and was a pun on his name. Later generations, after the language had changed, produced the pun we have here.
He was supposed to be licentious and mean.He was not ready for the Danes to renew their attack. They had been pretty docile since Alfred, the Great. He lost all of England. His son Edmund II Ironside, briefly recovered some of it, but then King Canute (and 2 other Danish kings) took over until Aethelred's other son, Edward the Confessor, regained the throne--only to lose it in the next generation to William the Conqueror.