Magnus I of Svealand (The Kalmar Union)

Magnus I/II Nielsen, Magnus the Unlucky, was a 12th century Scandinavian king who ruled over both Svealand and Viken, though not concurrently. Much of his reign would be overshadowed by a rivalry with the more successful Sverker.

Born in 1106 to Niels of Viken and Margaret Fredskolla, daughter of Inge I (the Elder), King of Svealand, Magnus was, from an early age in line to inherit both kingdoms. His early life is little known however it is clear he was present in Svealand, probably on his mother's estates when his cousin Inge II died. Magnus was accepted by the Svealandic nobles and Inge II's widow Ulvhild went to Viken to become Niels' second wife.

However he was isolated and the Svealandic nobility did not take kindly to the Vikene advisors Magnus had brought with him. Svealand was soon in rebellion and Magnus's position was soon untenable after increasingly violent clashes. Svealand elected Sverker of Gothenland as its new king

Defeated and deposed, Magnus slunk back to Viken. His father Niels I was in many ways a weak king and had largely left the real governing of the kingdom to his queen Margaret Fredskolla. Viken was indeed temporarily listless after her death and Magnus assumed much of the role of king by 1132. During this time he directed much of his energies to opposing Sverker and attempting to wrest Svealand back though in practice this extended little further than small-scale raids on Gothenland.

Little changed when Niels died and Magnus was crowned in his own right. However to soothe tensions and make peace Sverker's daughter, Helena, was betrothed to Magnus's son Cnut. Sverker then handed Magnus's confiscated Svealandic estates to the new couple, momentarily patching up relations but leaving a bone of contention between the two states for many years to come.

Magnus died in 1140 leaving the kingdom to his son Cnut.