In the Middle Ages the Bible was the subject of most learning and writing because it was the basis of Christian theology. It provided the foundation of study of history, science, and language as well. The Book of Genesis was especially important because it told of the beginnings and the human fall from grace. By the 12th century, biblical commentary had developed into a complex body of knowledge which still had to be redigested in order to deal with changes and new issues. Theologians coped with the difficulties by dividing knowledge into categories and organising it as units. Their books reflected these changes in their graphic layout. This copy of Genesis has an extensive gloss or commentary, but instead of writing the gloss between the lines or in margins as had been done earlier, the main text is written in a narrow column in the centre of the page with the commentary on either side. The main text is written in a larger script, the gloss smaller. The margins were free to note things like sources. Tall red letters make up the first words of Genesis 1 ('In the beginning...'). The commentary of Bede (c. 673-735), who had much to say about the first words, flanks the centre column. The 'footnote' referencing him can be seen in the margin. An inscription at the top says, 'Book of St Mary, Rievaulx,' to identify the owner, the great monastery in Yorkshire.