The illustrated bestiary, depicting real and imagined creatures, is a distinctive medieval construct. Bestiaries first appeared in England in the 12c and were derived ultimately from a Greek text, the Physiologus, from 4c Alexandria. They display a strange imagination alongside what we would consider a complete disregard for empirical or scientific assessment and judgement. There are fine versions, for example, in the Bodleian Library (MS 764), which is based on a version of 30 or so years earlier and dates to c. 1230; and in the library at Aberdeen University (MS 24), which dates to c. 1200. The bestiary, in displaying the 'wonders' of the world to its readers, was showing the wonders of God's way, in which could be found moral significance. For those who knew so little of the world beyond the immediate horizon, these images satisfied a deep hunger for the strange and wonderful. [< Lat. bestia = farm animal; beast for hunting]
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.