In late 2011, the Conservative and Liberal Democrat coalition government announced the launch of a new programme on 'troubled families' - a term used to describe the estimated 120,000 most behaviourally anti-social families in England and Wales. To many social scientists, this appeared to be yet another reconstruction of the broad 'underclass' concept that has run like a thread of analysis through UK poverty discourses over the last 150 years. The symbolic nature and coded meanings of this particular concept of poverty are very interesting, as is the way it has been reconstructed periodically. This paper summarises these reconstructions, and the analytical issues raised by them: the 'residuum' concept of the 1880-1914 period; the 'social problem group' of the inter-war years; the 'problem family' of the 1940s and 1950s; the 'cycle of deprivation' of the 1970s; and the 'underclass' of the 1980s and 1990s.