 Three other writings precede the first book; a prologue in verse, a preface in prose which treats of the origin and contents of the collection, and the aforesaid metrical panegyric on the rulers of the Carolingian line; beginning with Pepin and Carloman and ending with the sons of Louis the Pious.Four supplementary writings ("additamenta") are annexed to the last book; (I) The Aachen capitulary of 817 concerning the monasteries; (II) the report of the bishops (August, 829) to the Emperor Louis the Pious; (III) a few genuine capitularies and a large number of forged ones, just as in the main body of the collection; (IV) a large number (170) of extracts taken from various sources, among which are also forgeries of the Pseudo-Isidore.The work of Abbot Ansegisus was taken as a model for the collection.