[Footnote 51: The Codex Carolinus is a collection of the
epistles of the popes to Charles Martel, (whom they style
Subregulus,) Pepin, and Charlemagne, as far as the year 791,
when it was formed by the last of these princes. His
original and authentic Ms. (Bibliothecae Cubicularis) is now
in the Imperial library of Vienna, and has been published by
Lambecius and Muratori, (Script. Rerum Ital. tom. iii. pars
ii. p. 75, &c.)]