From the contents of this volume, one might get the impression that the cantor-historian was primarily a northern European phenomenon. Yet there is at least one known individual from southern Europe who composed a liturgical ordinal, performed liturgical music, studied liturgical history, wrote a chronicle of sorts and identified himself as a cantor. His name was Benedict, and he was a canon of St Peter's basilica at the Vatican in Rome. The book he wrote is entitled Liber politicus in the manuscripts. Paul Fabre, its modern editor, apparently thought this was a corrupt misspelling of Liber polyptychus, which would describe the book as many-sided, a polyptych or miscellany. Yet Fabre also thought this was a poor description of the book's actual content. Another possible emendation is the one published by Jean Mabillon in the editio princeps: Liber pollicitus, apparently ‘the promised book’. I propose we assume that Benedict meant what he wrote, and that we should understand the title to mean, ‘Book of the City’, an attempt to render Liber Urbanus into Greek. Urbanus would in fact be an accurate title, since the entire book is about Urbs, the city of Rome.

There are three extant manuscripts. The twelfth-century manuscript in Cambrai is the closest chronologically, but the farthest away geographically, and Fabre considered it the least faithful copy of the text. He preferred the two fifteenth-century Roman manuscripts. These two begin with a dedicatory epistle not found in the Cambrai MS, which has the following title:

Guido de Castello was appointed cardinal priest of S. Marco, in what is now the Piazza Venezia, in 1134. He reigned as Pope Celestine II in 1143–44. Thus the epistle was written after 1134, and its title shows awareness of the papal election of 1143. More information about the dating comes from a chronicle of the popes that forms part of the Liber politicus. The chronicle ends with Pope Innocent II, who reigned in 1130–43 and is called ‘dominus meus’.