'Rex Perpetuus Norvegiae' (from
Latin, "
Eternal King of
Norway") is an
honorific title that was given to King
Olaf II of Norway (Saint Olaf) in
1163. Ten years earlier, a new
archdiocese was established at
Nidaros by
Nicholas Cardinal Breakspear (later Pope Hadrian IV). In the new
Law of succession, the second
archbishop of Nidaros,
Øystein Erlendsson (Saint Øystein), decreed that future kings of Norway should not be considered kings in their own right, but rather as
vassals governing in the absence of Saint Olaf.