Although Queen Hiordis was one the rare Highland monarchs born before her grandfather's death, she followed family tradition by ascending the throne in her early twenties and dying before the age fifty. When King Sweyn III died young and without an heir following a long illness, Olof I, his brother and regent, was proclaimed king by the barons. Olof I died in his forties after little more than a decade on the throne, setting a pattern followed by his son, Olof II, and his granddaughter, Hiordis.
During Hiordis' reign, tensions with the eastern Lowlanders led to an outbreak of war between the Highland Kingdom of Excalbia and the Grand Duchy of Saxmere. Excalbia's armies, led by Prince Olof - later King Olof III - crushed the army of Grand Duke Michael I. The defeat forced Saxmere to offer its allegiance to Excalbia as a tributary.