Medieval families were rather fluid organisations. Due to high infant mortality and frequent premature parental deaths, medieval families would have experienced not only death as a far from unknown daily companion, but also step relationships. Historians have for some time stressed the importance of the wider community in the raising of children and young people in medieval society (examples include Professor Barbara Hanawalt), but many have still conceived of the peasant family as largely homogeneous in its constitution, Mainly nuclear, with more or fewer children surviving into their teens depending primarily on their social status and relative wealth. I would argue that the medieval peasant family was much much more complex. Step – parents would have been very common, half siblings due to re-marriage and the consequent re constitution of individual households. It is very difficult to assess the true extent of the impact of such step – families. In our contemporary society much anxiety is frequently expressed about step families, or the ‘declining traditional’ family. In 2011, according to figures published by the Office of National Statistics in May 2014, 11% of couples with dependent children were step families. This is perhaps a much lower figure than is often assumed, but still sizeable enough to make step families a common enough experience. Yet how ‘untraditional’ exactly would be such a family arrangement? Looking at my growing ( if still somewhat tentative data) of underaged heirs in later medieval English villages, we might find some interesting evidence that 11% is in fact a very low proportion of step families, and there is little that is ‘un-traditional’ about a family containing step children. Manorial court rolls provide us with some details concerning in whose care underaged heirs were left. Records drew a clear and above all, consistent distinctions between what was termed as the ‘mother of the heir’ and the ‘wife of the deceased’ the latter thus being the head of the household, the father, of the heir. Accordingly the wife, by implication, was not the mother of the heir, but the step -mother. If such records can be trusted, then to date my data seems to indicate that in about 17 to 18% of cases of underaged heirs the person left to look after them and their land was the step -parent, in most cases the step mother. This would provide some interesting statistical evidence of the extent of step families in a typical medieval English village. The next questions to ask then are the effects of this rather significant prevalence of step families on children and half siblings growing up within them.