certainty be attributed to the above earl, is the repairing and
extending the fortifications. Carew, in his _Survey of Cornwall_,
published in 1602, mentions the finding about sixty years before, 'of
certain leather coins in the castle walls, whose fair stamp and strong
substance till then resisted the assaults of time.' These singular
coins, if they had been preserved or their impressions had been copied,
might have thrown some light on the age of the building, as money of
similar _substance_ was employed by Edward I. in erecting Caernarvon
Castle in Wales, 'to spare better bullion,'[1] Some Roman coins have
likewise, according to Borlase, been found in this neighbourhood; so
that it is not unlikely that the Romans had possession of this fortress,
which, from its situation near the ford of the river Tamar, was a fort
of great importance. The earliest historical documents that are known
concerning the castle, mention the displacing of Othomarus de Knivet,
its hereditary constable, for being in arms against the Conqueror. It
was then, as before mentioned, given to Robert, Earl of Moreton, whose
son William, kept his court here. From him it reverted to the crown, but
continued attached to the earldom of Cornwall till Edward III. when it
was constituted and still continues, part of the inheritance of the
Duchy. In Leland's time, several gentlemen of the county held their
lands by _castle-guard_, being bound to repair and defend the
fortifications of this castle.[2] During the civil wars, this fortress
was garrisoned for the king, and was one of the last supports of the
royal cause in this part of the county."[3]

[1] Kennet's _Parochial Antiquities_.

[2] Leland says "the hill on which the Keep stands, is large and
of a terrible height, and the arx (i.e.) Keep, of it, having
three several wards, is the strongest, but not the biggest, that