Editing Olaf Tryggvason (section)

===Alliance with Emperor Otto II===
[[Holy Roman Empire|Holy Roman Emperor]] [[Otto II]] assembled a great army of [[Saxons]], [[Franks]], [[Frisia]]ns, and Wends to fight the [[Norse paganism|Norse pagan]] [[Denmark|Danes]]. Olaf was part of this army because his father-in-law was king of Wendland. Otto's army met the armies of King [[Harald Bluetooth]] and [[Haakon Jarl]], the ruler of Norway under the Danish king, at [[Danevirke]], a great wall near [[Schleswig]]. Otto's army was unable to break the fortification, so he changed tactics and sailed around it to [[Jutland]] with a large fleet. Otto won a large battle there, and forced Harald and Haakon with their armies to convert to Christianity. The constituents of Otto's army then returned to their homelands. Harald held to his new religion, but Haakon returned to worshipping the pagan gods when he came home.