MISC: He was the son of King Olav Haraldson, also known as Olav II or Saint Olaf.
Magnus grew up in Russia where his father had been in exile.
Age at death: About 23.
When his father's adversary, King Canute of Denmark and England, died in 1035, Magnus was summoned back to Norway from Russia by those who were loyal to his father. Magnus became king of Norway. He then helped King Hardecanute of Denmark against the Wends in return for an agreement that if either of them died without an heir, the other would succeed him; therefore, in 1042, Magnus I became king of Denmark. In 1043, he was victorious against the Wends. He united Norway and Denmark during his rule. He laid claim to the English throne also, but could not attain it. In 1046, he made his uncle Harald Hrdrde co-ruler with him. Magnus died the following year, and his uncle became King Harald III who was killed during the invasion of England in 1066.