A concise but comprehensive introduction in Italian and English helps the reader to collocate the Armorial in its correct historical context; special attention is given to the history of heraldic decorative arts and manuscript and bibliographical sources. The introduction is followed by the paleographic transcription of the hand-written notes to the coats of arms of the city families, and by the 1891 index of the reproduced coats of arms. This 18th-century Armorial – once the property of Ghiselli and then of a branch of the Malvezzi family – is now in a private collection in Paris and is made up of several heraldic manuscripts. It represents a fundamental source of information for the civic and religious history of Bologna. The main 1891 coats of arms can be attributed to two main artists. They include: 454 coats of arms of the capitani del popolo and podestà  (from 1258 to 1532); 188 coats of arms of the legates and pontifical governors (from 1327 to 1747); 32 coats of arms of bishops of Bologna (from 1154 to the early 18th century); 26 coats of arms of cardinals (18) and popes (8) from Bologna, all listed in chronological order; 97 coats of arms of families from the senatorial nobility(42 extinct and 55 still flourishing at the time of the publication); 862 coats of arms of city families (with very interesting hand-written information transcribed in the appendix); 15 coats of arms of the colleges. By other artists are the coats of arms (24) of people who governed the city in different periods, of the 30 Arts and Crafts – of which two versions are reproduced – and of the 45 spiritual companies. Still other two artists executed the coats of arms (34) of the chapters and religious institutions, and those (37) of the several chivalric orders, respectively. A final manuscript reproduces some fifteen heraldic monuments placed in the cloister of the Dominicans, with the relating coats of arms (19) and inscriptions. The appendix includes four heraldic plates attributed to Pasquali Alidosi, and one plate by an anonymous artist.