Dr Janina Ramirez begins her journey with the first Anglo-Saxon rulers to create a united England, encountering books in the British Library's Royal manuscripts collection which are over a thousand years old and a royal family tree which is five metres long. Janina finds out about a king who had a reputation for chasing nuns and reads a book created as a wedding gift for a ten-year-old prince. She roams from Westminster Abbey to other ancient English spiritual sites such as Winchester, St Albans and Malmesbury, and sees for herself how animal skins can be transformed into the finest vellum.

Janina shows how medieval manuscripts gave power to the king and united the kingdom in an age of plague, warfare and rebellion. She discovers that Edward III used the manuscripts he read as a boy to prepare him for his great victory at the battle of Crecy and reveals how a vigorous new national identity bloomed during the 100 Years War with France. In the British Library's Royal Manuscripts collection Dr Ramirez finds out that magnificent manuscripts like the Bedford Hours, taken as war booty from the French royal family, were adapted for the education of English princes. She also explores how knowledge spread through a new form of book - the encyclopedia.

The story of the British Library's Royal Manuscripts collection reaches its end with the last great flowering of illumination, in the magnificent courts of the Tudors. She investigates astrological texts created for Henry VII, and unwraps his will - still in its original, extravagantly-decorated velvet and gold cover. She hears music written for Henry VIII, which went unperformed for centuries; and reads love notes between the king and Anne Boleyn, written in the margins of a prayer book. Janina also visits Bruges, the source of many of the greatest manuscripts, where this medieval art form collided with the artistic innovations of the Renaissance.