Gratian's "Decretum" commentated by Bartholomew of Brescia.
Presented here is an example of the best-known text of medieval canon law used in 13th and 14th century European universities.https://www.loc.gov/resource/gdcwdl.wdl_19522/?sp=1&st=gallery
Gilded Manuscript created in Bologna, around the turn of the 14th century in the workshop of Niccolò di Giacomo da Bologna. However, the original text was compiled sometime in the 12th century in Bologna too by the well-known jurist Gratian (Gratianus).