Magnus VI of Norway

Magnus Haakonsson (Old Norse: Magnús Hákonarson, Modern Norwegian: Magnus Håkonsson; 1 (or 3) May 1238 – 9 May 1280) was King of Norway (as Magnus VI) from 1263 to 1280 (junior king from 1257). One of his greatest achievements was the modernisation and nationalisation of the Norwegian law-code, after which he is known as Magnus the Law-mender (Old Norse: Magnús lagabœtir, Modern Norwegian: Magnus Lagabøte). He was the first Norwegian monarch known to have used an ordinal number, although originally counting himself as "IV".