The Manuscript no. 3.307 in the National Library in Madrid that is one of the most important scientific codices of the 9th century. It was originally made up of seven books but only four have survived complete; all of the sixth book is missing and parts of the first and the seventh.
The Metz Codex is a copy of a now-lost original and was written around the middle of the 9th century in Metz, on the orders of Bishop Drogo. It is the best reflection we have of the Carolingian original dating from the first decade of the century.
It is written in Carolingian minuscule, a script which played an important part in Charlemagne's reforms.
The second chapter of Book V is entitled De ordine ac positione stellar in signis. It includes drawings of the fixed stars in the Ancient style which associated the stars with the forms of animals or mythical beings. Some of the constellations resemble the symbols of the signs of the zodiac, while others represent mythological characters.
The drawings in this treatise are outstanding aesthetically as well as scientifically. They were intended primarily as faithful copies of their Classical model and are in effect facsimiles of Latin and Greek works.