The tradition of reading specific portions of Scripture on certain days of the year began in a small way. Before the middle of the fourth century only the Gospel readings for Good Friday and Easter were traditional. By the end of the fifth century the readings on the six Sundays preceding Easter (Lent) had become traditional, and readings had also been established for Christmas and the two Sundays following it. By the end of the sixth century the readings on the five Sundays following Easter, the five Sundays preceding Christmas (Advent), and of the three Sundays preceding Lent, had become established. By the end of the seventh century the churches in and around Rome were using unofficial lectionaries which specified readings for every Sunday of the year. Towards the end of the eighth century the French king Charlemagne published such a lectionary, based upon one he had obtained from Rome, for the use of churches throughout his realm. At the end of the tenth century (AD 1000) this lectionary of Charlemagne, with a few local variations, had become traditional throughout the churches of Western Europe. The readings were still in Latin, as was the entire service. Only a small fraction of the people understood it, even in Rome.
In the sixteenth century, at the time of the Protestant Reformation, Martin Luther and his followers caused the Sunday readings to be done in German, but they continued to use the old lectionary. Likewise the moderate Protestants who took charge of the Church of England continued to use the old lectionary, with minor modifications. The more radical Calvinists in Switzerland, Scotland, and the Netherlands discarded the old lectionary, and adopted the custom of reading completely through selected books of the Bible.