The Codex Justiniani, called the 'Digest' or 'Pandects', goes back to 534 when the Emperor Justinian had imperial decisions and enactments compiled as part of his programme to codify Roman law. When law began to be studied in western European universities, starting with Bologna in the 11th century, the 'Pandects' became valued as basic legal texts. The need for huge textbooks like the Codex Justiniani fueled the development of workshops to produce books outside of monasteries. In England, Oxford became a manuscript producing centre, turning out books like this one, which was owned by Merton College. The page is packed full with the text of the 'Pandects' in two columns in the centre of the page, surrounded with wide margins which hold glosses (explanatory notes in margins or between the lines) in small handwriting. Some of the glosses are contemporary with the main text, but masters added others over the years. Decoration is minimal, major sections beginning with small portraits of kings, meant to depict Roman emperors--here is perhaps Gratian or Valerian, whose laws are presented. On the lower right, a tiny, odd-looking creature offers comic relief.