The Missal of Silos is the oldest known document on paper (as opposed to parchment) created in Europe; it dates to before 1080 AD.
The missal is "Codex 6" held in the library of the Monastery of Santo Domingo de Silos near Burgos, Spain.
This was suppressed in 1080 by Pope Gregory VII (something which helps date the manuscript).
[1] However, the monastic library continued to hold a collection of liturgical manuscripts of the rite until the 19th century when some were sold.
In 2013, the manuscript was inspected by Umberto Eco, who had referred to Silos in his 1980 novel The Name of the Rose.