The line of Olaf II ended with Magnus' death.
However, in 1280 Eric II of Norway, who was descended through his mother from Magnus' legitimate sister, Wulfhild, was crowned king of Norway.

Magnus was not married, but had a daughter out of wedlock, Ragnhild, who married Haakon Ivarsson, a Norwegian nobleman.
Her great-grandson would become King Eric III of Denmark.
The line of Olaf II ended with Magnus' death. However, in 1280 Eric II of Norway, who was descended through his mother from Magnus' legitimate sister, Wulfhild, was crowned king of Norway.
Magnus was not married, but had a daughter out of wedlock, Ragnhild, who married Haakon Ivarsson, a Norwegian nobleman. Her great-grandson would become King Eric III of Denmark.
Magnus the Good