(documents issued by the pope without being asked or being consulted upon a subject). Finally, under the name "decretals" are known certain collections, containing especially, but not exclusively, pontifical decretals. These are the canonical collections of a later date than the Decretum of Gratian (about 1150). The commentators on these collections are named decretalists, in contradistinction to the decretists, or those who commented upon the "Decretum" of Gratian. Eventually some of these collections received official recognition; they form what is now known as the "Corpus Juris Canonici". An account follows of the collections of decretals, particularly of those of Pope Gregory IX. Decretals are known by the first two Latin words that begin the letter, called the incipit. Decretal collections The early collections of decretals were not commissioned by the popes. A number of bishops collected decretals and tried to organize them into collections. Burchard of Worms and Ivo of Chartres made influential collections. From the Collectio Francofurtana (around 1180) onwards, collections get a more systematic character, and a school appears, the decretalists, who compile, organise and study the decretals as the basis of canon law. In quick succession, four so-called compilationes appeared between 1191 and 1226, as a sign of the growing importance of papal decretals. The fifth compilation, the Compilatio Quinta, was made by the canonist Tancred (d. about 1235) for Honorius III in 1226, who sent it immediately to the University of Bologna. It was organized into five books. Pope Gregory IX commissioned the Dominican Raymund of Peñafort to edit a comprehensive collection of papal decretals. This collection of nearly 2,000 decretals appeared in 1234 as the Decretales Gregorii IX, also known as the Liber Extra, which was also immediately sent to the universities of Bologna and Paris. In 1298, Pope Boniface VIII published the next major collection of decretals. He entrusted three canonists with its redaction. This collection is known as the Liber Sextus. In the 14th century, a few small collections followed: the Constitutiones Clementinae or Clementines (1317), edited by Anastasius Germonius and published by pope John XXII, and the Extravagantes Johannes XXII (1325–1327). Collections are known as systematic or primitive, the chief distinguishing characteristic being the use of headings to organize the work. This organizational scheme makes a collection systematic. Quinque Compilationes Antiquae Decretalium The Decretum of Gratian was considered in the middle of the 12th century as a corpus juris canonici, i. e.