Codex epistolaris Carolinus
From Clavis Canonum
The Codex epistolaris Carolinus (or simply Codex Carolinus) is a collection of 99 papal letters. Charlemagne in 791 had all papal letters sent to him, his father, and his grandfather collected. The only extant manuscript is Wien, ÖNB, Cod. 449. The letters are arranged by pontificate, but little if any chronological order is preserved within the letters of individual popes. The earliest two letters are by Gregory III, written in 739 and 740; the largest number of letters in the Codex Carolinus are by Hadrian I.
