Why are illuminated manuscripts called “illuminated”?

Those medieval books were literally lit, man.

Illuminated manuscripts are crowded with fantastic beasts, intricate greenery, and elaborate initials framing miniature scenes from either the Bible, apocryphal histories, hagiography, or simply folk stories and legends. Today,they continue to captivate bibliophiles and art fans, both secular and religious alike.

In his classic Renaissance and Renascences in Western Art, the German art historian Erwin Panofsky explained the Italian Renaissance was preceded by at least two major revivals of Greek and Roman antiquity. One of these was the 9th-century Carolingian “renaissance,” which Panofsky understood as a revival of classical forms that influenced styles of lettering and decoration, most of them now preserved in the National Library of France.