Denmark was forged under threat from the Holy Roman Empire to the south. Responding to Henry the Fowler's 934 invasion, the pagan king Gorm the Old raided the southern frontier, securing Jutland. His successor Harold Bluetooth precluded further invasions by Christianizing Denmark, fortifying the Danevirke, and establishing massive military camps. Harold's son Svein inherited a Danish kingdom with European-wide ambitions.
