Johannes Teutonicus (Johann Zemeke), a German canonist trained at Bologna, compiled the Apparatus on Gratian's Decretum around 1216 — the great running gloss that drew together the work of the earlier decretists and became the glossa ordinaria of the Decretum. He served as provost of the Halberstadt cathedral chapter and later as bishop-elect, and was active at the Fourth Lateran Council (1215), on whose canons he also wrote an apparatus. His gloss on the Decretum, revised by Bartholomaeus Brixiensis around 1245, dominated the teaching of canon law for the rest of the Middle Ages and was incorporated into every standard printed edition of the Corpus Iuris Canonici through the early modern period.
