Æthelred the Unready was an English king who ruled from 966 to 1016. His reign was marked by constant Viking invasions, which led to significant challenges for his kingdom. The nickname "Unready" comes from the Old English word "unræd," meaning ill-advised or poorly prepared, reflecting his struggles in leadership and decision-making. Despite his difficulties, Æthelred attempted various strategies to defend his realm, including paying off the Vikings with large sums of money known as Danegeld. His reign ended with his death in 1016, after which his son, Edmund Ironside, briefly took the throne before facing further Viking challenges.