"Book illustration in printed books seems to have completed in one generation (ca. 1460—ca. 1490) a cycle which took about 1,000 years in manuscript illumination. In early blockbooks and in the typographically produced books of [Albrecht] Pfister, illustrations performed an almost separate function; they were not subservient to the text. (In the earliest extant illuminated manuscripts from the Vth—VIth century, as for example the Vienna Genesis, illustrations were similarly 'independent.) Beginning in the 1470's illustrations in printed books became more and more integrated into the text, achieving an aesthetic harmony of the two elements. (In illumination this development lasted from the IXth to the XIVth century). By the end of the XVth century illustrations in many printed books began to outgrow the text page; the artist freqeuently paid less attention to the character of the type, and the unity of type and illustration decreased. (This development is examplified in many Books of Hours where, outside the calendar illustration [which remained subjunct to the text], the pictorial aspect occupied an inordinately large place; in manuscripts we can observe this from the early XVth century on.). This dichotomy did not apply to incidental illustrations, used to adorn title pages or the text, nor to some of the finest XVIth-century illustrated books (like [Hans] Holbein's Dance of Death)" (Hirsch, Printing, Selling, Reading 1450-1550  120; there are 3 footnotes in Hirsch's book, which I have incorporated into the quotation where indicated, using parentheses).