Michael the Syrian
Over a hundred Syriac Orthodox dioceses and around a thousand bishops are attested between the sixth and thirteenth centuries. The main source for these dioceses and bishops are the lists of Michael the Syrian, compiled in the twelfth century. Many other dioceses and bishops are mentioned in other literary sources, particularly the works of Bar Hebraeus, written in the second half of the thirteenth century. Several bishops not known either to Michael the Syrian or Bar Hebraeus are mentioned in the colophons of surviving West Syriac manuscripts.