King Magnús ascends to the throne after the premature death of his brother Hákon the young, and the demise of his father King Hákon the old in Orkney. His reign begins with the crown established as the factual power in Norway and as an expanding power in the North Atlantic. King Magnús embarks in a most ambitious legal reform, which replaced the four provincial codes of Norway for a National code and had an impact in the laws of the tributary lands of the crown, most specially for Iceland.