The oldest known document or codex written on paper in Europe is the
Missal of Silos. A quarto comprised of 157 folios, of which folios 1-37 are on paper and the remainder on parchment. It has been described as a breviary-missal or a
Liber Mysticus or
Breviarum gothicum.
"The missal is "
Codex 6" held in the library of the
Monastery of Santo Domingo de Silos near
Burgos, Spain. It is one of a number of liturgical manuscripts of the
Mozarabic rite which have been preserved in the Silos library, despite the suppression of the rite in 1080 by
Pope Gregory VII. The codex is named after its current location in Silos, but it was not made at the Silos monastery's
scriptorium; it was made at the monastery of
Santa María la Real of Nájera. The paper for the missal is believed to have been manufactured in the Islamic world, probably
Islamic Spain, even though
Nájera was in Christian territory at the time the document was created" (Wikipedia article on Missal of Silos, accessed 9-2020).