While the Anglo-Saxons understood natural science within a framework of Christian doctrine, it represented a secular facet of their knowledge. This manuscript contains a calendar, a map of the world, astronomical materials, and a 'Marvels of the East' (on the strange inhabitants of other parts of the world). Written in Old English and Latin, it is one of the most lavishly illustrated secular books of the early middle ages. Nonetheless, its origins are not easily determined. Its features point to Canterbury, Winchester and Gloucester, with current opinion supporting Christ Church, Canterbury. How it was used is unknown: it is so unique nothing compares with it. In the 12th century it belonged to the library of Battle Abbey. The calendar has entries for Christian feasts and saints' days, but these often take a back seat to astronomical and astrological dates of interest. This page begins with the month of May and goes into June, under the sign of Taurus, the bull, shown in a roundel in the lower right corner. At the top, a scene of shepherds and their flocks represents the labour of the month, a conventional series of occupations associated with each month depicted in medieval calendars. A verse on the zodiac and a note on the number of the month's solar and lunar days heads the page. Prominently written in large letters, notes of the days of the beginning of summer ('Aestatis initium') and the sun's moving into the sign of Gemini ('Sol in geminos') stand out from the church feasts.