De testibus tractaturi, an unedited late twelfth-century, southern Italian treatise, draws on both Gratian’s Decretum and decretals of Pope Alexander III to consider question concerning witnesses. It may also be influenced to some degree by the Summa of Simon of Bisignano. There is no evidence of any reliance on
civilian authors. In considering the exceptio contra personam testis, it raises the question of whether testimony given by a witness who later died before trial remained valid. This subject is rarely treated in the early canonistic ordines iudiciorum. The author’s application of a letter of Alexander III to Bishop Roger of
Worchester (JL 13162) to this question appears to be unusual, perhaps unique, and sheds light on how the early ius commune evaluated evidence.


Keywords: De testibus tractaturi; Gratian; Simon of Bisignano; Pope Alexander III.