The Standard Edition of the Corpus Juris Canonici. Originally published: Leipzig: Tauchnitz, 1879-1881. 2 Vols. civ, 1472 columns (736 pp.); lxxxii, 1340 columns (670 pp.). Attempts to codify the body of canon law began in earnest during the Carolingian Empire. These efforts reached fruition between 1020 and 1025 in the Decretum of Burchard, Bishop of Worms. The next great step was taken in 1151 with Gratian's Concordia Discordantium Canonum, or Decretum Gratiani, a watershed compilation that superseded earlier collections. The Libre Quinque Decretalium of Gregory IX followed in 1234. Published in 1298, the Liber Sextus of Boniface VIII was the last great collection of the pre-Reformation era. John XXII added the final collection, the Liber Septimus Decretalium, better known as the Clementinae in 1317. Three more texts were added later: the Extravagantes of John XXII (1325), the Extravagantes Communes of other popes to 1484 and the Appendix Pauli Lancellotti (1563). This body of writings assumed the collective title of the Corpus Juris Canonici. Between 1580 and 1582, they were revised by the Correctores Romani, a commission established by the Council of Trent. Its edition remained the law of the Western Church until the promulgation of the Code of Canon Law in 1917, which remains the current law of the Roman church. Published from 1879 to 1881, Friedberg and Richter's critical edition, one of the great philological projects of the nineteenth century, remains the standard version of this work. Emil Albert Friedberg [1837-1910] was a professor of law at the University of Leipzig and a supporter of state supremacy in ecclesiastical matters. This can be seen from his most noted publications which include: Die Die Geschichte der Zivilehe (second edition, 1877), Verfassungsgesetze der evangelisch-deutschen Landeskirchen (1885) and Lehrbuch des Katholischen und Evangelischen Kirchenrechts (fifth edition, 1903). Aemilius Ludwig Richter [1808-1864] was a professor of canon law at the University of Marburg. Some of his students include Richard Dove, Paul Hinschius, Emil Friedberg and Johann Friedrich von Schulte, who were the leading canonists of the later decades of the 19th century. Richter wrote many significant textbooks including Treatise on Catholic and Protestant Church Law (Eighth edition, 1842) and History of the Lutheran Church Constitution (1851).