 Haakon killed Magnus on the island of Egilsay in April 1116.This led to the "martyrdom" of Magnus and the construction of St Magnus Cathedral in Kirkwall.After the death of Magnus "Hakon took over the whole of Orkney and made all those who had previously served Magnus swear oaths of allegiance... and made those of Earl Magnus' friends who had been most hostile to him pay heavily for it in tribute".