Harald Hardrada

At fifteen, Harald Sigurdsson fought beside his half-brother Olaf at Stiklestad in 1030, lost, and fled into exile. He served Grand Prince Yaroslav in Kievan Rus', then moved to Constantinople around 1034, rising to command the Varangian Guard and amassing wealth through campaigns across the Mediterranean, Asia Minor, and Sicily. In 1046 he returned to claim Norway, striking a deal to share the throne with his nephew Magnus - who died a year later, leaving Harald sole ruler. He spent nearly two decades raiding Denmark in a failed bid to rebuild Cnut's North Sea empire, then pivoted in 1066 when Tostig Godwinson invited him to take England. Harald sailed with three hundred longships, crushed the northern English forces at Fulford on 20 September, and was killed five days later at Stamford Bridge when Harold Godwinson's army caught him off guard.