Magnus the Strong, also known as Magnus Nilsson, was a Danish duke who ruled Gothenland in southern Sweden from the 1120s to c. 1132. It is disputed whether he was elected king by the Swedes, but he is nevertheless sometimes found in the modern list of Swedish monarchs as Magnus I. Snorri Sturlason gives him the epithet "Strong".

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.