Each medieval town had such a strong sense of identity that we tend to think of them as social and economic units, and talk of a whole town prospering and declining. Our purpose here is to examine the individuals living in towns, and we cannot assume that their changing wealth and living standards coincided precisely with the growth or decay of the urban community to which they belonged. The thirteenth century was a period of urban expansion, yet many of the people who crowded into the larger centres or who formed the population of the new market towns were clearly making a precarious living as occasional wage-earners and petty traders. Likewise later in the period, and especially in the fifteenth century, many larger towns went into decline, suffering a loss of population, a shrinkage of the built-up area and a diminution in commerce and industry. Some small towns declined so far as to lose their urban character. Even in these circumstances, individuals would not necessarily have experienced long-term impoverishment. They could have migrated from declining places to towns that retained their prosperity, like London or Exeter, or to one of the small towns or industrial villages where the expanding cloth industry was often located. One of the main symptoms of urban decline was not so much the wholesale emigration of the inhabitants, but the failure of the place to continue to attract immigrants.