Magnus II Haraldsson, elder son of Harald Hardrada, ruled Norway (1066–1069) after his father fell at Stamford Bridge, sharing the kingship with his brother Olaf III until an early death.
When Harald Hardrada sailed for England in 1066 he left his elder son Magnus behind as king of Norway — a precaution that saved the dynasty when Stamford Bridge destroyed the invasion. Magnus, about eighteen, was already holding the kingdom when his brother Olaf brought the survivors home.
The brothers divided the kingship in 1067 in the customary Norwegian manner, Magnus taking the north. He died of disease in April 1069, barely twenty-one, and Norway passed whole to Olaf Kyrre's long peace.
Magnus was born around 1048 to Harald Hardrada and Tora Torbergsdatter of the powerful Giske kin — the marriage that bound the Arnmødling magnates to the new dynasty. He was named for his father's nephew and predecessor Magnus the Good.
His only recorded independent command came in 1058, when — a boy of ten, clearly under guardians — he nominally led a Norwegian fleet to support Ælfgar of Mercia and Gruffudd ap Llywelyn in Wales; the episode shows how early Hardrada put his sons into the dynasty's work.
The sagas, which lavish attention on his father and brother, give Magnus little beyond the essentials, and honesty requires saying so: he appears as the responsible elder son, trusted with the realm at eighteen, and as a king who kept his half of a divided inheritance without recorded conflict with his brother — itself noteworthy in a century when joint kingships regularly ended in war.
Morkinskinna preserves the tradition that the division of 1067 was amicable and that Magnus's early death, not rivalry, reunited the kingdom. Against the vivid saga portraits of Hardrada's ferocity and Olaf's quietness, Magnus survives as the dynasty's dutiful, briefly-glimpsed hinge.
Magnus's kingship was framed by the catastrophe of 1066: he was regent-king while his father and brother sailed with the great fleet, and the settlement of 1067 made formal what the disaster had made fact — Magnus king in the north at Nidaros, Olaf in the east, the customary Norwegian double kingship rather than any partition of sovereignty.
In April 1069 Magnus sickened and died at Nidaros of what the sagas call "ringworm disease", commonly identified with ergotism. He was buried in Christ Church — the predecessor of Nidaros Cathedral — near the shrine of his uncle Saint Olaf, and his infant son Håkon Toresfostre would briefly figure as a king a generation later.
Magnus's quiet three years mattered for what did not happen: no succession war after Stamford Bridge, no Danish reconquest, no magnate revolt. The stability he and Olaf kept let Norway absorb the loss of its king, its fleet, and a generation of warriors in a single September week.
His line continued through his son Håkon, co-king with Magnus Barefoot for a year, but the future belonged to Olaf's and then Magnus Barefoot's descendants; Magnus II remains the least remembered king of his house — the price of dying young in peace.