The population of England declined by around fifty percent during Chaucer’s lifetime, mainly as a result of plague. Apart from much grief, this also created dislocation, opportunity, growing social mobility and rising expectations, which were vigorously resisted by the rich and powerful. Social awareness increased, and with it social stratification, not only among the aristocracy, with the emergence of new ranks such as marquis and viscount and a closely defined peerage, but also among the middling and poorer ranks of society. Terms such as ‘gentleman’ and ‘yeoman’ became common as social signifiers of those who were inferior to the knights and esquires who made up the gentry, but superior to the mass of the peasantry. Such demarcation lines were never absolute, but they were not crossed unobtrusively. This social awareness is reflected in the Canterbury Tales. Some of the individual pen-portraits of the pilgrims in the General Prologue appear to present aspirations rather than reality, yet behind this lies an unmistakable echo of the social fluidity of the age, a topped-and-tailed cross-section of a society in transition.