The earliest extant substantive illuminated manuscripts are from the period 400 to 600, produced in the Kingdom of the Ostrogoths and the Eastern Roman Empire. Their significance lies not only in their inherent artistic and historical value, but also in the maintenance of a link of literacy offered by non-illuminated texts. Had it not been for the monastic scribes of Late Antiquity, most literature of Greece and Rome would have perished. As it was, the patterns of textual survivals were shaped by their usefulness to the severely constricted literate group of Christians. Illumination of manuscripts, as a way of aggrandizing ancient documents, aided their preservation and informative value in an era when new ruling classes were no longer literate, at least in the language used in the manuscripts.
The majority of extant manuscripts are from the Middle Ages, although many survive from the Renaissance, along with a very limited number from Late Antiquity. The majority are of a religious nature. Especially from the 13th century onward, an increasing number of secular texts were illuminated. Most illuminated manuscripts were created as codices, which had superseded scrolls. A very few illuminated fragments survive on papyrus, which does not last nearly as long as parchment. Most medieval manuscripts, illuminated or not, were written on parchment (most commonly of calf, sheep, or goat skin), but most manuscripts important enough to illuminate were written on the best quality of parchment, called vellum.
Beginning in the Late Middle Ages, manuscripts began to be produced on paper. Very early printed books were sometimes produced with spaces left for rubrics and miniatures, or were given illuminated initials, or decorations in the margin, but the introduction of printing rapidly led to the decline of illumination. Illuminated manuscripts continued to be produced in the early 16th century but in much smaller numbers, mostly for the very wealthy. They are among the most common items to survive from the Middle Ages; many thousands survive. They are also the best surviving specimens of medieval painting, and the best preserved. Indeed, for many areas and time periods, they are the only surviving examples of painting.