The Gospel Book, Evangelion, or Book of the Gospels (Greek: Εὐαγγέλιον, Evangélion) is a codex or bound volume containing one or more of the four Gospels of the Christian New Testament — normally all four. The term is also used of the liturgical book, also called the Evangeliary, from which are read the portions of the Gospels used in the Mass and other services, arranged according to the order of the liturgical calendar.
Liturgical use in churches of a distinct Gospel book remains normal, often compulsory, in Eastern Christianity, and very common in Roman Catholicism and some parts of Anglicanism. Protestant churches normally just use a complete Bible.
In the early Middle Ages, the production of copies of the Bible in its entirety was rare, if only because of the huge expense of the parchment required. Individual books or collections of books were produced for specific purposes. From the 4th century Gospel Books were produced for liturgical use, as well as private study and as "display books" for ceremonial and ornamental purposes. The Codex Washingtonianus (Freer gospels) is an early example of a book containing only the four gospels, in Greek, written in the 4th or 5th century. By the 7th century particular gospel texts were allocated to days in the liturgical calendar; previously gospel readings had often worked through the books in sequence. Many of these volumes were elaborate; the Gospel Book was the most common form of heavily illuminated manuscript until about the 11th century, when the Romanesque Bible and Psalter largely superseded it in the West. In the East they remained a significant subject for illumination until the arrival of printing. The Evangelist portrait was a particular feature of their decoration. Most of the masterpieces of both Insular and Ottonian illumination are Gospel Books, and there are very many Byzantine and Carolingian examples.