Which European country has the longest, unbroken monarchy?

Explanation

Historians agree that both Denmark and England have had rulers who called themselves kings dating back to the 8th century. As a fixed institution, the English monarchy is the oldest. It dates back to Alfred the Great, who ruled over Southern England 871-899. Denmark, on the other hand, has had the most continuous monarchy, dating back to Gorm the Old, who died around year 958.