 Later, during the reign of David II, the "Mac Cailinmor" ever becoming more powerful, since the marriage of Sir Neil Campbell with a sister of Robert I, were resisted from taking control of the clan by the "Mac Arthur" branch with the obtaining of a charter "Arthuro Campbell quod nulli subjictur pro terris nisi regi," by Arthur Campbell.In 1427 James I held parliament at Inverness and summoned the Highland chiefs.Iain MacArthur, the chief of the MacArthurs, was one of the unlucky chiefs who were beheaded by the king of Scots.