He held
canonries in the
dioceses of
Aberdeen and
Caithness when, in 1263, he was elected
Bishop of Caithness. As is usual with bishops of Caithness, very little is known about Walter's episcopate. It is known he received a subsidy from the king taken from the profits of justice in the province. According to
Clan Mackay tradition, Aodh Mór MacAoidh (or Iye Mackay), married a daughter of Bishop Walter, acquiring 12
davochs of land at
Durness. ==Death==