[Footnote 63: The first crown or regnum (Ducange, Gloss.
Latin. tom. v. p. 702) on the episcopal mitre of the popes,
is ascribed to the gift of Constantine, or Clovis. The
second was added by Boniface VIII., as the emblem not only
of a spiritual, but of a temporal, kingdom. The three
states of the church are represented by the triple crown
which was introduced by John XXII. or Benedict XII.,
(Memoires sur Petrarque, tom. i. p. 258, 259.)]