This some would derive from a French original, as being pres d’eaux,
near the waters; for that the sea formerly flowed up as high as this
place, till the stream works choaked up its entrance, any one that
views the high cliffs under this place, and those on the opposite side
of the valley in Tywardreath, must needs be convinced of. And this
leads me to another etymology for it, and as suitable to its
situation, from Pir or Prid, clay, and Aus, the same with Als, the
cliff or sea-shore.
But be this how it will, Prideaux Castle herein was for several ages
(probably before the Norman Conquest) the seat of, and gave name to a
family which hath been very eminent both in this county and in
Devonshire, and still flourisheth in both. Thomas de Prideaux
represented this county in the Parliament 26 Edward I. and Roger de
Prideaux was Sheriff of Cornwall 15 Edward III. His father Dominus
Thomas Prideaux de Prideaux, was one of those who had in the 25th of
Edward I. 20_l._ per annum or more, in lands or rents in this county,
which he held by knight’s service. This family gave for their arms,
Party per pale Azure and Gules, three castles Counterchanged; which
arms are now quartered by Mr. Prideaux of Padstow, who is descended,
as well as all of the name, from younger branches of the family
residing here.