Harald Hardrada was a Norse king known for his military prowess and ambition. Born around 1015 in Norway, he became a prominent figure in Viking history. After years of serving as a mercenary in Kievan Rus and Byzantine Empire, he returned to Norway and claimed the throne in 1046. In 1066, Harald attempted to expand his rule by invading England, believing he had a legitimate claim to the crown. He faced King Harold II at the Battle of Stamford Bridge, where he was ultimately defeated and killed, marking the end of the Viking Age in England.