Hildegaard ascended the throne in Citadel Excalbia at the age of 16 following the death of her father, King Sweyn II, in battle against the Lowlanders. Many of the Highland nobles chaffed at the idea of a woman wielding the Sword of the monarchy. A few, led by the Barron of Turaida, staged an insurrection against the young queen. The rebels planned to place one of their own - Hildegaard's cousin, Gustavus - on the throne in her place.
To the surprise and dismay of the barons, Hildgegaard personally led her army into battle. Her bravery soon won her support from those nobles who had originally opted for neutrality and the genuine affection of most Highlanders.
Hildegaard finally defeated the rebellion in 1677, personally slaying the Baron of Turaida and Gustavus in battle on the Plains of Turaida.
The young warrior queen married Lord Dzirdis, the captain of her army, shortly after ascending the throne in 1674 and bore her first son, who later became King Sweyn III, while encamped with her army in 1675. Despite her enthusiasm for outdoors activity and her widely reputed stamina and physical endurance, the queen fell gravely ill in 1697. After two years of debilitating coughs, periodic fevers and great pain, Hildegaard finally died in 1699 at the age of 41.