Niels was the King of Denmark from 1104 to 1134. Niels succeeded his brother Eric Evergood and is presumed to have been the youngest son of King Sweyn II Estridson. King Niels actively supported the canonization of Canute IV the Holy and supported his son Magnus I of Sweden after he killed his rival for the succession, Knud Lavard. His secular rule was supported by the clergy. Niels was killed in an ensuing civil war and succeeded by Eric II Emune.

Eric I, also known as Eric the Good, was King of Denmark following his brother Olaf I Hunger in 1095. He was a son of Sweyn II. His mother's identity remains unknown. He married Boedil Thurgotsdatter.