Not proof exactly, but certainly confirmation of some details.
http://thornews.com/2014/11/10/%EF%BB%BFanalysis-of-skeletal-remains-confirms-king-sverris-saga///cdn.embedly.com/widgets/platform.js
A genealogical journal
Not proof exactly, but certainly confirmation of some details.
http://thornews.com/2014/11/10/%EF%BB%BFanalysis-of-skeletal-remains-confirms-king-sverris-saga///cdn.embedly.com/widgets/platform.js